I'd be surprised if OW declared for anyone other then the south considering how poorly the Northern realm's treat them. Then again, they are stuck up there so it'd be smart to play neutral for a while.
Believe me, Ohnar gets no more than it deserves. And they'd be fools to declare for the south. They're surrounded by Sorraine and Arcaea, so the only contribution they could make would be to attack our lands directly, and from behind. They...would not survive the attempt.