I'm watching the match right now, and oh man, it was insane. There were just some absolutely AMAZING ralies.
The guys really probably should have put it away in 2 sets, but it's ok, they pulled it out in the end.
Based on what the commentators are saying, Paes/Zimonjic won the group and the twins second, so I Guess they'll play the winners of the other group...
Edit: never mind, because three groups were tied at 2-1 win-loss and the Bryans and Paes/Zimonjic had the same sets win-loss, that tie was broken by the head-to-head and since the twins beat Paes/Zimonjic, they DID officially win the group