Sun Java SE 6 Update 4 has released. From the release notes, it has more than 370 bug fixes.

For end users, you may want to update your Java JRE v1.6.0_04 soon.

http://java.sun.com/javase/downloads/index.jsp
http://java.sun.com/javase/6/webnotes/ReleaseNotes.html#160_04