The account stealing scams are starting early this year. Many players received e-mails this week from a company that appeared to be Blizzard, inviting them into the Wrath of the Lich King beta. The link in the e-mail even took you to a very well done front page that asked you for, you guessed, your account name and password.
Blizzard let everyone know that this week that they have not issued any beta invitations and that any e-mails you may have received are false and, most likely, account stealing scams. They also went on to list resources they have previously posted that help prevent players from losing accounts, equipment and gold from these kinds of scams: