The arena rankings don't lie, and it shows it's the same problem as on retail. Arena players want to play with other good players, and if a critical mass of players is reached on a certain faction, it just feeds on itself. We've reached that situation here, and I don't see how it could be fixed short of allowing cross-faction arena.
Having said that, for filthy casual bg'ers like myself, you can win bgs a lot more than you lose as horde by doing premades. Not as much as on alliance premades, but it's still a lot of fun (most days, today wasn't too much fun lol), and the instant queues are great. It must be pretty grim as a solo queue horde trying to gear up, though.