I'll make this short and sweet. I updated my iPod touch software to 3.1 and my iTunes to 9.0, both announced today (among other things you can find on the Apple Website. I installed iTunes thorough the iTunes program, checking for software update. It downloaded iTunes 9.0, Quicktime Player 7.6.4, and restarted my PowerBook.
I started iTunes. Anytime I accessed the iTunes store it crashed. So, I manually downloaded iTunes 9.0. It works fine now.
See 3.1 features and iTunes 9.0 features for more information.