Lylirra has posted on the forums with an official message regarding the account hacking epidemic of Diablo III accounts. As another reminder, make sure your account is protected and that you steer clear from any shady links, no matter how much candy is placed on top of it.
Blizzard has still not directly said what has happened, and they have not revealed anything specific… at all, really. Bashiok has also gone around on threads addressing people, and even calling some out on their false claims. It seems that they stand by the security the authenticator provides… and I, too, am inclined to believe it is a safe option for your security.
UPDATE 1: Blizzard has added a further response regarding the issue of hacking:
If you believe your account may have been compromised, please notify our support department as soon as possible. Contact information and instructions for account recovery can be found at http://us.battle.net/en/security/help on our Blizzard Support page. We will do all that we can to assist.
Additional security steps (which we highly recommend reviewing) are also available online. For more information visit: http://us.battle.net/en/security/checklist
We also wanted to reassure you that the Battle.net Authenticator and Battle.net Mobile Authenticator (a free app for iPhone and Android devices) continue to be some of the most effective measures we offer to help players protect themselves against account compromises, and we encourage everyone to take advantage of them. In addition, we also recently introduced a new service called Battle.net SMS Protect, which allows you to use your text-enabled cell phone to unlock a locked Battle.net account, recover your account name, approve a password reset, or remove a lost Authenticator. Optionally, you can set up the Battle.net SMS Protect system to send you a text message whenever unusual activity is detected on your account, keeping you aware of important (and possibly unwanted) changes.
For more information on the Authenticator, visit http://us.battle.net/support/en/article/battle-net-authenticator-faq
For more on the Battle.net Mobile Authenticator, visit http://us.battle.net/support/en/article/battle-net-mobile-authenticator-faq
For more on Battle.net SMS Protect, visit http://us.battle.net/support/en/article/battlenet-sms-protect
We also have other measures built into Battle.net to help protect players. Occasionally, when Battle.net detects unusual login activity that differs from your normal behavior — such as logging in from an unfamiliar location — we may prompt you for additional information (such as the answer to one of your security questions) and/or require you to perform a password reset through the Battle.net website. World of Warcraft players might be familiar with this security method already, and Diablo III players may begin to encounter it as well.
As always, if you think you’ve been the victim of an account compromise, head to the “Help! I’ve Been Hacked!” tool at http://us.battle.net/en/security/help for assistance.