Jaap van den Herik (https://chessprogramming.wikispaces.com/Jaap+van+den+Herik) predicts that, within 20 years, a computer will beat humans at playing Diplomacy.

I think that is a quite interesting challenge, but high profile? too few people know that game.

Also, measuring that the computer is better will be problematic, as humans (or, for that matter, computers) could conspire to let one of their own ilk win.