Icon that is displayed in the installer window (only affects the progress panel which is currently built using MSI) and in the Add and Remove panel should be the Java icon and not the default MSI installer icon. See the attached screen capture of the Add and Remove panel.
16px version:
http://jre.us.oracle.com/java/re/j2se/7/promoted/latest/ws/deploy/src/plugin/win32/graphics/java-icon.ico