I got mine yesterday. Aside from AT&T screwups (we cancelled your data plan sir. We shoved the sim in back to front sir") the only real problem I have is it vibrates when the volume is turned up. Like the speaker is loose. I've been tweeting, browsing facebook, couple of games, texts and 3 calls.
There does appear to be a bug with the Skype preview that is causing hangs - you might want to try uninstalling that if you have it installed.