I've already read that the Destruction (read Horde) side is the most populated.
I came across some funny posts concerning choosing a side for RvR in Warhammer.
I think we will be faced with what I call the Richard Hatch phenomenon. Richard Hatch was the first winner of the Survivor series. Richard craftily formed voting alliances, which was ingenious at first but then was copied for seasons to come.
Many players started playing WoW without thinking about PvP. Many, not coming from a gaming background, didn't know much about the game at all. Those in the know, and those focused on PvP chose Horde. Those not in the know suffered and usually since you don't find out how bad things are until max level, you've made friends, good guilds, find it hard to start over.
But with the knowledge of things from WoW will you choose blindly (read prettily)? Or have you learned from the master(s) that choosing a side for looks isn't the best choice when you want to (or have to) compete. Sure the people in the first Survivor were blind-sided by Hatch's cunniness, but what excuse did all the remaining Survivor tribes have?
The big difference is PvP was only a part of WoW. PvP is Warhammer, so perhaps both sides have good pvp racials if there is such a thing. And perhaps both sides will balance out as far as populations are concerned. (How will they balance populations anyway???)
I'm going to admit that I haven't learned anything and that I'll probably choose whatever seems "cool" to me first. But I'm not going to think twice about switching if things turn out as they did in WoW*.
*Please remember my decision to take a break from WoW and try something else had nothing whatsoever to do with PvP.
7 hours ago