But there is SatoshiDICE, which is designed along similar principles and seems to get some use.
I guess part of the problem is that people who play roulette are not very sophisticated about it, since it's an expected loss anyway. I could imagine poker players being interested, but this protocol doesn't really fit: it reveals what the deck was at the end of the round (players who folded do not want other players to know what their hand was). I think that the attack that online poker places worry the most about is colluding players, and P2P cryptography doesn't help there.
Intrade, the prediction market website, has shutdown. According to their website:
With sincere regret we must inform you that due to circumstances recently discovered we must immediately cease trading activity on www.intrade.com.
These circumstances require immediate further investigation, and may include financial irregularities which in accordance with Irish law oblige the directors to take the following actions:
During the upcoming weeks, we will investigate these circumstances further and determine the necessary course of action.
Here's a link to an article on the slashdot website with more information about it:
http://slashdot.org/topic/bi/intrade-shuts-down-under-murky-circumstances/
Has anyone looked into the feasibility of creating an open source version of something similar, using a distributed application and a microcurrency (such as bitcoin), that couldn't be shutdown?