That information is highly subjective.
The top rated 2v2 team is a Hunter/Druid team. But that doesn't mean that any Hunter/Druid team will perform any better than any other 2v2 team. It doesn't even mean that a Hunter/Druid team has more potential to become highly rated than any other 2v2 team. It just means that these two individuals, in the gear they have, have crafted the teamwork and skill of play necessary to be the top rated 2v2 team.
But don't let that keep you from looking for a Resto Druid for your 2v2 Arena team. :)