So no Mergea and no Petzschner (no GGL either). Not a lot of interesting teams on this list but Groth/Qureshi and Khachanov/Rublev look like dangerous floaters.
I also like the look of Kyrgios/Reid, Haase/Middelkoop and Knowle/Peya. Pospisil/Zimonjic is odd as is Paes/Raja but they could be dangerous too.
The Pospisil/Zimonjic pairing caught my eye. Zimonjic is 41 and frankly doesn't seem to be in the greatest shape, but he's a multi-Slam champion who definitely knows how to play doubles. Pospisil, much younger & fitter, has some experience and success in dubs but has never dedicated himself full-time to doubles because he's always simultaneously pursued a singles career. Still, he's a Wimbledon champion who definitely has skills on the doubles court. With Zimonjic's savvy and Pospisil's talent, this team could make a dent in the draw.