No, but this option has always been in the back of my head. This has just been a weekend project for the past few months, and is still in alpha, but once I get to a stable/secure release this option will be explored.
That's an interesting idea. Given how flexible the bitcoin transaction script system is, it might be possible to set up a system where the bitcoins can only be claimed by someone who can prove that they won.
The bitcoin script system only really allows by hashing. People have gotten very hyped up about the programmability of the scripting system in Bitcoin, but anything slightly interesting still requires trust in one or more arbitrators.
But less trust than the currently used alternatives. In a 2 out of 3 transaction you have to trust the arbitrator is not colluding with the other person, but you don't have to worry about him taking the money for himself.
Yes, this seems like the most likely arrangement - in a poker game if a significant fraction of your opponents are colluding without your knowledge then you're in trouble anyway, so you already have that level of trust. If you can use the same level of trust to claim the prize as you already implicitly have - maybe that 2/3rds of the players systems agree that a particularly player won, that would probably be good enough.
Another approach might be that everyone playing a game also automatically randomly observes another game somewhere, and their view of what happened is added to the trust calculation.
Give it a little time. After being an early adopter, bitcoin has pretty much bored me to death recently but this new idea of DACs, protoshares etc. has me interested again like bitcoin originally did.
DAC stands for distributed autonomous corporation. "Corporation" in this context is a little bit wonky because bitcoin is a DAC. I could see there being both general gambling DACs or specific to poker. It takes a little while to wrap your head around the concept, so I will just give you some reading: