Couldnt find anything about this so here it is:
U go specc the specc were u can get 2x2handed weapons as Warrior.
U go respecc to the specc u like, Suddently u can use 2hands + shield or 2x2hand without the specc like with arms specc and what so ever..
This i surely a bug that will be removed, but for now, go use it..
It damn pwnz