I have been in the Diablo III beta for two nights now. At this point it sucks because I can't play.
I got to play a little last night, but it keeps losing connection to the server. If you've kept up, you have to be connected to the server in order to play, even if you are playing the single-player game. They've said some things but we all know it is for two reason which are not in any particular order: anti-piracy for one. And two, the real-money auction house where you can buy and sell items and they really want to make sure you aren't going to cheat. But watching the server go up again down like (insert inappropriate joke about your mom here) you can see where the concept is slightly flawed.
The worst part, and the reason I am so frustrated, is that the launcher gives you an error that is a number that tells you nothing. I think I have seen three different error numbers but I don't know what they mean. At first I thought maybe there was something wrong on my end, but at least I on the forums this isn't the case. The last post from Blizzard was over two hours ago and said the server is back up, which is then immediately followed a few minutes later by a billion posts from people who can't get on. Nothing else official has been posted.
Oh, and I can't post on the forums. I get "This account has limited posting access due to the following condition: This game license has expired or been cancelled."
I tried to search their forums for what this problem was related to, but all the information I could find was related to the old Starcraft II beta and not relevant. I went to their customer service section and filled out the web form, of course their neatly organized categories didn't really come anywhere close to the problem I was having. I picked something that seemed relevant if you squint. Hopefully it will get passed along to the right department.