All of its features are great, I've seen all of them, but you know, it's not going to help in any signature technique really.Maybe in rendering and retouches, some animations and stuff.Not really in Avatars/Signatures.You could work with CS4 for these stuff, there won't be any big change in those.Especially I like the Mini-Bridge feature, the content-aware of course and the Puppet Warp tool.The healing brush has some improvements too.
I think I got some links but I'm not sure if they're working...
-Blane