Playing just battlegrounds and also playing arenas are two very, very, very different things. Either spec will be fine for battlegrounds, ghost wolf isn't as important since realistically there isn't really a need to "get away" in BGs, if you die you die no big deal, 30 seconds later you will rez up and continue.

Just curious but do you think you will only play BGs at 80? Also lake WinterGrasp is really a different ballgame as well, to be honest as a multiboxer it might be best just to spec 2-3 resto and play more defensively in Wintergrasp, since the initial assaults rely so heavily on vehicle combat.