That's been proposed in the bay12 forums several times. While I don't think that Tarn ever officially responded, the reason that's not going to happen seems to

That's been proposed in the bay12 forums several times. While I don't think that Tarn ever officially responded, the reason that's not going to happen seems to boil down to it requiring a complete rewrite of all the code behind the game. Which isn't going to happen any time soon - I recall that, a while back, he was using implementing new features as a reward to get him to do bugfixes; putting off the fun things until after he'd done the unfun things. Rewriting all of the code would be extremely unfun, take forever, and prevent implementing new features.