I am going to report tentative success with 3.0.1, but only after a factory restore then update. The key for me seems to have been iTunes 9.0.2; things seem to be working smoothly after that update.
I had been holding off on the iTunes update due to reported problems (
http://discussions.apple.com/thread.jspa?threadID=2217792 ), and before I did it the Apple TV was giving all sorts of trouble, freezing or rebooting itself after a sync, while I was trying to browse around.
It could be that the prior version of iTunes was syncing something the Apple TV didn't like. It could be that I simply neglected to sync a troublesome file to the Apple TV this time around. It could be that the problems will return. I'm not sure.