Here's where I think the technique would work beautifully: high-stakes heads-up poker. Collusion isn't an issue in HU because it's just you versus exactly one other opponent. Your main concern would be a crooked site operator peeking at your hole cards and then sharing that information with your opponent. Mental poker solves that problem nicely.

Disconnects wouldnt' be an issue either becuase you could just forfeit the disconnecting player without being unfair to anyone else.
Woohoo! I think we just invented 'provably fair' heads-up poker! Now back to coding...