If you're an Annual Pass holder, keep your eye on your email.
It's finally time for regular folks to get their hands on the 'Mists of Pandaria' beta. Those invited into the beta test – all Annual Pass holders included – will be getting emails over the next few weeks or so and will then be instructed to download the expansion from Battle.net.
The current beta only covers the levels 1-10 starting zone, but you can still copy your high-level characters over so you can check out the new talent system. And of course, since this is a real Beta instead of a promotional tool, the game will be changed and tweaked often.
Be careful with those emails and don't click any of the links in them. 'Warcraft' in particular is a phishing target, so if you're selected, head over to Battle.net to confirm.
Source: World of Warcraft