I've just finished a game of Diplomacy, playing as Germany, on Facebook; I have agreed a draw with Russia, after France dropped out - I could almost certainly have pushed my advantage and gained an extra three centres to get to the magic 18, but it would have been a rather hollow victory, and I felt I could live with the shared glory of a draw.
I used to be a big fan of postal Diplomacy; in the various archives you will find misguided advice from me on playing Turkey, and other such ephemera. I was also the second president of the Cambridge University Diplomacy Society, which I'm glad to say is still going strong. (The guy who founded the society went straight into the British diplomatic service after graduation, and is now an ambassador in central Asia.)
I dabbled occasionally with the email versions on the various Judge computers, but never quite got the hang of it - I see my ranking is about 14,000th out of 21,000, though one of my successors as DipSoc President is currently the highest rated player.
However, I like the Facebook interface a lot more. I'm not wild about the maps - took me a while to work out how to read them - and I'm not wild about the way you have to check to see how close you are to the deadline. But the basics of running the moves and communicating with other players seem to work OK.
I do wonder if there is a greater propensity for people to miss deadlines in Facebook games. In the other one I'm in at the moment, I'm clinging on with a single centre as Russia after myself missing the Spring 1901 deadline. In the one that has just finished, England and France both missed two deadlines and went into civil disorder. But I guess it just shows that the most important criterion for winning the game is to simply stay in it. (I remember a game back in my postal days where I fought back from two centres to ten thanks to a similar fortuitous dropout [Edited to add: Sad to say I just discovered that the conscientious Tom Tweedy, who GMed that game and invetned the rules for postal Sopwith, died on Christmas Day].)
Anyway, this is not going to be the obsession that Scrabulous was, back in the day; but if I have one or two games going at a time, it's a pleasant enough diversion.