If you're using any kind of IP blocker, such as PeerGuardian to allegedly protect you while downloading torrents, it's likely set to block internet traffic to and from Activision Blizzard. If that's the case, set those Blizzard IP addresses to always allow, or turn off your IP blocker temporarily. Then try to go where you were going in WoW again, e.g. battleground, dungeon, etc.