As far as I know, they have no plans to remove BWL or MC from Cataclysm, because they don't want to remove a player's chance to get old legendaries.

They are, however, adding two new areas in assocation with BWL: Blackrock Caverns and Blackwing Descent. The former is a dungeon, the latter is a raid if I remember correctly.

Grats on getting into Beta. Are hunters as awesome as I hear they are?