Get it hot! 
As I’ll probably be waiting for this release to hit the/some Gentoo/Ubuntu repo, I have to say I’m surprised at the seemingly short interval between the last update releases. Seems 11 was only last week somehow.
As my previous Athlon64 and current Intel i7 Core are both 64bit, I do have to say I’m anxious to try the long announced java plugin for 64bit platforms. I’ve been using icedtea 6 on gentoo for a while, but as I need a Sun JVM for professional stuff I’m glad this update has finally arrived. Curious to see if it lives up to it’s expectations.
Besides all that, the included improvements seem quite numerous (take a look at the release notes)