Drysc from Blizzard had the following to say in response to all the changes being made in WoW PvP, or lack thereof.
Regarding spec viability we would definitely like to see every spec at least partially viable, that doesn't mean however that each spec will be equal in a very cutthroat PvP environment like the arenas. A prot warrior or shadow priest or what have you should though be able to jump into a battleground or arena and be able to do something with some small amount of success. How much success that should be is really the question, but our general philosophy is that we're ok with some specs not being as viable as others, we sort of have to be.