Java Plug-in 11.0.0.41
JRE 1.8.0-ea-b41 on MacOS X 10.7.4

I've installed first 7u6 b12 from jre*.dmg file. Additional meddling with the system was, renaming /Library/Internet Plug-Ins/JavaAppletPlugin.plugin and creating a symlink
of /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin/Contents/Home/lib/deploy/JavaControlPanel.prefPane to /Library/PreferencePanes .

Now, I've opened http://java.sun.com/products/plugin/1.4/demos/jfc/SwingSet2/SwingSet2.html in Safari and typed into a TextField with some spectacular success.

Then, I've installed on top of it all jre from jdk8 b41. Now, whenever I open Safari and try something like typing in a TextField, I get AccessControlException, access denied, in case of a TextField in replaceKeyboardFocusManager privilege. There seems to be no obvious way to fix that.