And Kalgan says that Blizzard realizes this, and as a result, they are still not happy with the way 2v2 is balanced out-- Kalgan says that there are a lot of classes "left out of having a reasonable chance" to compete in the format, because of the "endurance" nature of the game. In fact, Blizzard almost went with a 4v4 Arena instead (in addition to the 3v3 and 5v5 teams now in the game), and abandoned the 2v2 idea entirely. The reason 2v2 stayed is that Kalgan agrees that players should be able to grab a friend and play. So Blizzard apparently took on the bigger challenge of balancing 2v2 just to keep players who didn't have lots of great PvPing friends in the Arena game.
Was it worth it? I've played both 2v2 and 5v5 formats, and I'd have to say that 2v2 is an interesting format, but the players angry about balance are right-- there are just some fights that can't be won in 2v2. I don't know if that's reason enough to have decided against it and gone with 4v4 instead (and I also don't think that there are lots of players that have friends enough to play 2v2 and not one of the bigger brackets), but Blizzard does have a long road ahead of them if they want to make 2v2 seriously balanced. Depending on how many people they've got playing there (my hunch is that 5v5 is much more popular, but that's just a hunch, I haven't seen the numbers), that may not be a road worth traveling.