WotF is only useful against fearcomps. AT is useful anywhere. Making undeads considerably better against fearcomps but rather useless against those that don't have that ability.
^ What he said. If you ONLY want to Pvp I'd say stay Alliance since Alliance racials -> Horde in matter of PVP racials (Especially human). But if you really want to go Horde because of friends or anything else you should definitly go Blood Elf for the Arcane Torrent. Will of Forsaken isnt as OP as it used to and will only be good against Fearcomps as previous posters already mentioned while Arcane Torrent will always be useful against anything you can silence.