Put me down for what this person said. I just want to have fun. I think the question for bioware is, once current issues are smoothed out, can they implement some form of arena style pvp without alienating a huge portion of the playerbase? If they can, it is worth it because arena is downright fun, and a ton of people are going to love it. It just can't give any useful rewards, like the best gear.
I do think arena could completely kill the potential for open world pvp in this game. Personally, I would prefer arena. But hey, if more people are interested in open world pvp than arena, then arena might be a bad idea.
The entire balance complaint seems silly to me. If arena highlights imbalances in 2v2 or 3v3 arrangements and that upsets you, don't fight in those numbers and go back to what you were doing before. What you should tell bioware is, don't homogenize the classes for the sake of balance in every configuration of fighting, but it doesn't make sense to disallow players from fighting in those configurations to mask an already present imbalance.