WildStar has PvP? I didn't, but then again I only started paying attention after the PAX East housing reveal.
As it turns out, one of WildStar's "elder games" is arena PvP. The game's latest dev diary outlines 2v2, 3v3, and 5v5 matches, and it also mentions a unique wrinkle or two. For instance, WildStar arenas aren't single-elimination but rather a series of slugfests wherein each team tries to get the opponent to use up its allotment of respawns.
There's more, of course, but you'll need to head to the WildStar website to read it.