Greetings fellow gamers,
just wanted to give you a heads up that I received an e-mail with the title Diablo 3 Beta invitations stating that I need to return my information, that is, battle.net e-mail, password, first name blahblah, in order to become eligible for the D3 Beta. The e-mail was sent from noreply@blizzard.com and I tracked it further to diablo3@d3-blizzard.com.
While the addresses may seem legitimate to someone who never took the time to check, they are not. Nobody is ever going to ask you for your password except when you are logging into Battle.net or a game, do not believe this, delete the e-mail and if you're even more paranoid run an antivirus and antispyware check.
Additional note: the e-mail came to an address that I have stopped using for WoW a long time ago, and instead have a new one when the battle.net merge became mandatory.