Hmm iTunes hangs? Since updating my Apple TV to version 3.0/3.0.1 I regularly either have to restart iTunes on my iMac (most common fix), restart the Apple TV by pulling the plug and reconnecting it, or once I had to reboot my wireless router after the above two "fixes" didn't work. My guess is it's an iTunes streaming problem but there are dozens of people with similar experiences over at the Apple Discussion forums.
I have had similar problems when adding content to my TimeCapsule and into iTunes and my Apple TV. It just seems a little buggy. Apple TV also does weird things when streaming, especially watching trailers. They take WAY LONGER and reload a bunch of times while watching for no reason.
Also, everyone remember that whole COMPLETELY REWRITTEN Finder and how FAST it was supposed to be? Why is it the when I start up my MacBook Pro and open the Finder the first time, it literally takes like 5-8 seconds just to load the application icons in column view???