I hadn't even considered this possibility, I got my beta key the other day by pre-ordering from gamestop. However, I can across a very recent article (http://www.blizzplanet.com/blog/comments/blizzplanet_starcraft_ii_beta_keys_twitter_giveaway/) that says that the beta keys provided at the very least for that contest WILL NOT work with the mac client. I was hoping someone could confirm/deny this. I'm going to be very unhappy if I can't use my beta key for the mac client, as this is my primary operating system. Until seeing this article I wouldn't have even considered this as something blizzard would do because it seems downright stupid to keep people from playing on multiple operating systems.

tl;dr please tell me that I will be able to use a gamestop beta key for the mac client.

PS I didn't really scan the forum too intensely for topics about this, so I apologize in advance if theres already a thread answering this question.