As with previous waves, it’s going to take a while for the invites to process, so we recommend checking your games list in Battle.net Account Management to see whether yours has arrived yet. Once it does, you’ll see the Mists of Pandaria beta client available for download from there. We expect this entire wave to take a day or so to complete.
We appreciate the enthusiasm of everyone who signed up for the World of Warcraft Annual Pass, and we’re working hard to get you into the beta. We know you’re excited to explore Pandaria and test the new content, and we’ll keep you posted here in the forums when we’re ready to send out another wave.