Have gotten 2 keys too. When it was previously reported a while back they were the same key send twice by accident but the second one I got today was different and it worked. Got to do a nice birthday present with that one :)
Played WoW since its beta, got my battle.net account the day they launced it, also have diablo 3 and starcaft in my account. WoW beta is the first and the last I got from Blizzard so far. 1 goddamn beta in 7 years. Keep up the good work guys.