Tripod Tom: You can always aggree with your opponent on the outcome and one of you resigns the game or aggree on a draw, if that's the case.
I suppose having the computer automatically check these situations would be computationally hard to do on every turn, and a big strain on the server (just think of how many moves are played each day by hundreds of players).

But I have a request for this and other situations - what if one of the players could call uppon such an algorithm manually? Take chess, for instance - it has precise rules about draws. Over a number of moves without capture anything, or repeating 3 times the same position. This puts a strain on the server if checked for every game, but if there was an option to call such algorithms at player's request, it would allow to quickly and automatically solve those games that now require a lot of explaining to do for beginner opponents or sometimes an administrator's intervention when you end up with a stubborn opponent that doesn't want to finish a lost or drawn game...