Lots of little features and toys, including mainly tighter security for web browsing.
You'd think it would include some utility or driver for hibernation, but nope.
Any ideas? It's still hanging on shutting down some programs (and this happens with AIM off, too).
Edit, 10:30 CDT Sun 05 Sep 2004: I should mention I was having this problem before; I just thought SP2 might help eradicate it.