NHL conferences are already unbalanced, largely because Detroit whined about being in the west and the NHL folded. There's 16 in the East and 14 (now 15) in the West.. They'll look to add another team, my guess is Quebec City, but maybe Seattle.. If it is Quebec, then Columbus will likely move to the West.
In terms of Vegas, they're going to be picking a bunch of crap players in the expansion draft, so it's not like they're going to be that competitive for a while.