JDK crash, not aware of any action in NetBeans that might have caused it.
Filed in bugzilla http://netbeans.org/bugzilla/show_bug.cgi?id=210958.

Crash log attached.

# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x00007fff8cf34b00, pid=89989, tid=6279364608
#
# JRE version: 7.0_04-b19
# Java VM: Java HotSpot(TM) 64-Bit Server VM (23.0-b20 mixed mode bsd-amd64 compressed oops)
# Problematic frame:
# C [libsystem_c.dylib+0x60b00] tiny_free_list_add_ptr+0x72
#
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
Here are more snippets from the hs_err_pid file:

--------------- T H R E A D ---------------

Current thread (0x00007fb6f8ac2800): JavaThread "BasicPanelVisual-prepareAdditionalProperties" daemon [_thread_in_vm, id=1984397312, stack(0x0000000176278000,0x0000000176478000)]

siginfo:si_signo=SIGSEGV: si_errno=0, si_code=1 (SEGV_MAPERR), si_addr=0x00007fb6f4f2310e

Registers:
RAX=0x000000000000fffb, RBX=0x00007fb6f4e00000, RCX=0x000007fb6f4e2316, RDX=0x00007fb6f4e23160
RSP=0x0000000176475928, RBP=0x0000000176475930, RSI=0x000000010c9ac800, RDI=0x000000010c9a7000
R8 =0x000000000000003f, R9 =0x00007fb6f84c94e0, R10=0x00000000000fffb0, R11=0x00000000ffbfffff
R12=0x000000010c9ac800, R13=0x000000010c9a7000, R14=0x00007fb6f4e23110, R15=0x0000000176470005
RIP=0x00007fff8cf34b00, EFLAGS=0x0000000000010202, ERR=0x0000000000000006
  TRAPNO=0x000000000000000e

Top of Stack: (sp=0x0000000176475928)
0x0000000176475928: 0000000000000001 0000000176475970
0x0000000176475938: 00007fff8cf3e711 07f900071c00fd07
0x0000000176475948: fffffffffffffff0 0000000000000006
0x0000000176475958: 00007fb6f84c8cf0 000000010c9aaa00
0x0000000176475968: 0000000176475d00 0000000176475a70
0x0000000176475978: 00007fff8cf3f00e f4002b00f1002700
0x0000000176475988: 0000000000000005 0000000000001e00
0x0000000176475998: 0000000000000048 000000010c9aaa00
0x00000001764759a8: 0000000001017a00 000000010c9ad068
0x00000001764759b8: 000000010c9ad050 000000010c9ad060
0x00000001764759c8: 000000010c9ad058 4500830000000005
0x00000001764759d8: 000000010c9ac804 000000010c9ad078
0x00000001764759e8: 0200230100000005 0000000376000d00
0x00000001764759f8: 000000010c9ac800 000000010c9ad070
0x0000000176475a08: 000000010c9ac800 fffffffffffffff0
0x0000000176475a18: 0000000000000004 000000010c9a7000
0x0000000176475a28: 01005501c7000a00 0200f30000003b02
0x0000000176475a38: 01b8370000000300 c72b4c0102b62aff
0x0000000176475a48: 0000000000000048 0000000000000006
0x0000000176475a58: 00007fb6f84c8cf0 000000010c9a7000
0x0000000176475a68: 0000000176475d00 0000000176475aa0
0x0000000176475a78: 00007fff8cf743c8 00eb00290026000d
0x0000000176475a88: 0000000000000048 0000000176475cd8
0x0000000176475a98: 0000000176475d00 0000000176475ac0
0x0000000176475aa8: 00007fff8cf751a4 000000400204ee00
0x0000000176475ab8: 0000000000000048 0000000176475ae0
0x0000000176475ac8: 000000010cf313df 0000000000000048
0x0000000176475ad8: 0000000176475cd8 0000000176475b00
0x0000000176475ae8: 000000010cfc6c4a 0000000176475b98
0x0000000176475af8: 0000000176475cd8 0000000176475b40
0x0000000176475b08: 000000010cfc7815 0000003c76475b40
0x0000000176475b18: 0000000176475b88 00007fb6f1c12a30

Instructions: (pc=0x00007fff8cf34b00)
0x00007fff8cf34ae0: c0 0f 00 41 f7 d3 49 83 c2 01 46 21 9c 93 a8 c0
0x00007fff8cf34af0: 0f 00 66 83 f8 02 72 12 44 0f b7 d0 49 c1 e2 04
0x00007fff8cf34b00: 66 41 89 44 12 fe 66 89 42 10 66 85 c0 75 04 66
0x00007fff8cf34b10: 89 42 10 4d 85 c9 74 58 48 8b 87 58 13 00 00 48

Register to memory mapping:

RAX=0x000000000000fffb is an unknown value
RBX=0x00007fb6f4e00000 is an unknown value
RCX=0x000007fb6f4e2316 is an unknown value
RDX=0x00007fb6f4e23160 is an unknown value
RSP=0x0000000176475928 is pointing into the stack for thread: 0x00007fb6f8ac2800
RBP=0x0000000176475930 is pointing into the stack for thread: 0x00007fb6f8ac2800
RSI=0x000000010c9ac800 is an unknown value
RDI=0x000000010c9a7000 is an unknown value
R8 =0x000000000000003f is an unknown value
R9 =0x00007fb6f84c94e0 is an unknown value
R10=0x00000000000fffb0 is an unknown value
R11=0x00000000ffbfffff is an unknown value
R12=0x000000010c9ac800 is an unknown value
R13=0x000000010c9a7000 is an unknown value
R14=0x00007fb6f4e23110 is an unknown value
R15=0x0000000176470005 is pointing into the stack for thread: 0x00007fb6f8ac2800


Stack: [0x0000000176278000,0x0000000176478000], sp=0x0000000176475928, free space=2038k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
C [libsystem_c.dylib+0x60b00] tiny_free_list_add_ptr+0x72
C [libsystem_c.dylib+0x6a711] tiny_malloc_from_free_list+0x416
C [libsystem_c.dylib+0x6b00e] szone_malloc_should_clear+0x45b
C [libsystem_c.dylib+0xa03c8] malloc_zone_malloc+0x4d
C [libsystem_c.dylib+0xa11a4] malloc+0x2c
V [libjvm.dylib+0x3ae3df]
V [libjvm.dylib+0x443c4a]
V [libjvm.dylib+0x444815]
V [libjvm.dylib+0x4448a6]
V [libjvm.dylib+0x444bd0]
V [libjvm.dylib+0x1547d0]
V [libjvm.dylib+0x15bd2b]
V [libjvm.dylib+0x15cc59]
V [libjvm.dylib+0x44a1fb]
V [libjvm.dylib+0x2c2e8d]
V [libjvm.dylib+0x2c3021]
C [libjava.dylib+0x1cd6] Java_java_lang_ClassLoader_defineClass1+0x199
J java.lang.ClassLoader.defineClass1(Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;

Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
J java.lang.ClassLoader.defineClass1(Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
J java.lang.ClassLoader.defineClass(Ljava/lang/String;[BIILjava/security/ProtectionDomain;)Ljava/lang/Class;
J org.netbeans.JarClassLoader.doLoadClass(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Class;
J org.netbeans.ProxyClassLoader.selfLoadClass(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Class;
J org.netbeans.ProxyClassLoader.loadClass(Ljava/lang/String;Z)Ljava/lang/Class;
J java.lang.ClassLoader.loadClass(Ljava/lang/String;)Ljava/lang/Class;
v ~StubRoutines::call_stub
j org.netbeans.modules.maven.newproject.BasicPanelVisual.prepareAdditionalProperties(Lorg/netbeans/modules/maven/api/archetype/Archetype;)V+45
j org.netbeans.modules.maven.newproject.BasicPanelVisual.access$900(Lorg/netbeans/modules/maven/newproject/BasicPanelVisual;Lorg/netbeans/modules/maven/api/archetype/Archetype;)V+2
j org.netbeans.modules.maven.newproject.BasicPanelVisual$6.run()V+8
J org.openide.util.RequestProcessor$Task.run()V
j org.openide.util.RequestProcessor$Processor.run()V+219
v ~StubRoutines::call_stub
hs_err isn't ported to MacOS X yet so here's a manual decode
using the sorted output from "nm libjvm.dylib":

Stack: [0x0000000176278000,0x0000000176478000], sp=0x0000000176475928, free space=2038k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
C [libsystem_c.dylib+0x60b00] tiny_free_list_add_ptr+0x72
C [libsystem_c.dylib+0x6a711] tiny_malloc_from_free_list+0x416
C [libsystem_c.dylib+0x6b00e] szone_malloc_should_clear+0x45b
C [libsystem_c.dylib+0xa03c8] malloc_zone_malloc+0x4d
C [libsystem_c.dylib+0xa11a4] malloc+0x2c
V [libjvm.dylib+0x3ae3df]
   00000000003ae3c4 T __ZN2os6mallocEm
   00000000003ae414 T __ZN2os10split_pathEPKcPi

V [libjvm.dylib+0x443c4a]
   0000000000443c15 T __ZN6SymbolnwEmi
   0000000000443c7a T __ZN6SymbolC1EPKhi

V [libjvm.dylib+0x444815]
   00000000004447a0 T __ZN11SymbolTable16allocate_symbolsEiPPKhPiPP6SymbolP6Thread
   0000000000444854 T __ZN11SymbolTable9basic_addE18constantPoolHandleiPPKcPiS4_PjP6Thread

V [libjvm.dylib+0x4448a6]
   0000000000444854 T __ZN11SymbolTable9basic_addE18constantPoolHandleiPPKcPiS4_PjP6Thread
   0000000000444a28 T __ZN11SymbolTable15allocate_symbolEPKhiP6Thread

V [libjvm.dylib+0x444bd0]
   0000000000444b7c T __ZN11SymbolTable3addE18constantPoolHandleiPPKcPiS4_PjP6Thread
   0000000000444c6e T __ZN11SymbolTable6lookupEPK6SymboliiP6Thread

V [libjvm.dylib+0x1547d0]
   0000000000153e58 T __ZN15ClassFileParser27parse_constant_pool_entriesE18constantPoolHandleiP6Thread
   00000000001548f8 T __Z4hashP6SymbolS0_

V [libjvm.dylib+0x15bd2b]
   000000000015bc10 T __ZN15ClassFileParser19parse_constant_poolEP6Thread
   000000000015c814 T __ZN15ClassFileParser14parseClassFileEP6Symbol6HandleS2_11KlassHandleP13GrowableArrayIS2_ER13TempNewSymbolbP6Thread

V [libjvm.dylib+0x15cc59]
   000000000015c814 T __ZN15ClassFileParser14parseClassFileEP6Symbol6HandleS2_11KlassHandleP13GrowableArrayIS2_ER13TempNewSymbolbP6Thread
   000000000015f470 T __ZN15ClassFileParser18is_klass_referenceE18constantPoolHandlei

V [libjvm.dylib+0x44a1fb]
   000000000044a12c T __ZN16SystemDictionary19resolve_from_streamEP6Symbol6HandleS2_P15ClassFileStreambP6Thread
   000000000044a424 T __ZN16SystemDictionary26handle_parallel_super_loadEP6SymbolS1_6HandleS2_S2_P6Thread

V [libjvm.dylib+0x2c2e8d]
   00000000002c2c62 t __ZL23jvm_define_class_commonP7JNIEnv_PKcP8_jobjectPKaiS4_S2_hP6Thread
   00000000002c2eff T _JVM_DefineClassWithSourceCond

V [libjvm.dylib+0x2c3021]
   00000000002c2faa T _JVM_DefineClassWithSource
   00000000002c3055 T _JVM_DefineClass

C [libjava.dylib+0x1cd6] Java_java_lang_ClassLoader_defineClass1+0x199
J java.lang.ClassLoader.defineClass1(Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;

Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
J java.lang.ClassLoader.defineClass1(Ljava/lang/String;[BIILjava/security/ProtectionDomain;Ljava/lang/String;)Ljava/lang/Class;
J java.lang.ClassLoader.defineClass(Ljava/lang/String;[BIILjava/security/ProtectionDomain;)Ljava/lang/Class;
J org.netbeans.JarClassLoader.doLoadClass(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Class;
J org.netbeans.ProxyClassLoader.selfLoadClass(Ljava/lang/String;Ljava/lang/String;)Ljava/lang/Class;
J org.netbeans.ProxyClassLoader.loadClass(Ljava/lang/String;Z)Ljava/lang/Class;
J java.lang.ClassLoader.loadClass(Ljava/lang/String;)Ljava/lang/Class;
v ~StubRoutines::call_stub
j org.netbeans.modules.maven.newproject.BasicPanelVisual.prepareAdditionalProperties(Lorg/netbeans/modules/maven/api/archetype/Archetype;)V+45
j org.netbeans.modules.maven.newproject.BasicPanelVisual.access$900(Lorg/netbeans/modules/maven/newproject/BasicPanelVisual;Lorg/netbeans/modules/maven/api/archetype/Archetype;)V+2
j org.netbeans.modules.maven.newproject.BasicPanelVisual$6.run()V+8
J org.openide.util.RequestProcessor$Task.run()V
j org.openide.util.RequestProcessor$Processor.run()V+219
v ~StubRoutines::call_stub



C [libsystem_c.dylib+0xa11a4] malloc+0x2c
V [libjvm.dylib+0x3ae3df] __ZN2os6mallocEm
V [libjvm.dylib+0x443c4a] __ZN6SymbolnwEmi
V [libjvm.dylib+0x444815] __ZN11SymbolTable16allocate_symbolsEiPPKhPiPP6SymbolP6Thread
V [libjvm.dylib+0x4448a6] __ZN11SymbolTable9basic_addE18constantPoolHandleiPPKcPiS4_PjP6Thread
V [libjvm.dylib+0x444bd0] __ZN11SymbolTable3addE18constantPoolHandleiPPKcPiS4_PjP6Thread
V [libjvm.dylib+0x1547d0] __ZN15ClassFileParser27parse_constant_pool_entriesE18constantPoolHandleiP6Thread
V [libjvm.dylib+0x15bd2b] __ZN15ClassFileParser19parse_constant_poolEP6Thread
V [libjvm.dylib+0x15cc59] __ZN15ClassFileParser14parseClassFileEP6Symbol6HandleS2_11KlassHandleP13GrowableArrayIS2_ER13TempNewSymbolbP6Thread
V [libjvm.dylib+0x44a1fb] __ZN16SystemDictionary19resolve_from_streamEP6Symbol6HandleS2_P15ClassFileStreambP6Thread
V [libjvm.dylib+0x2c2e8d] __ZL23jvm_define_class_commonP7JNIEnv_PKcP8_jobjectPKaiS4_S2_hP6Thread
V [libjvm.dylib+0x2c3021] _JVM_DefineClassWithSource
C [libjava.dylib+0x1cd6] Java_java_lang_ClassLoader_defineClass1+0x199