Okay I've pretty much deep sixed my game engine hacking for ubicomp dreams, but every now and then something comes across the transom that's worthy of note.
Don't know how good GarageGames Torque Game Engine is but it must be halfway decent if Tribes 2 was done in it. The price ($100 USD) is pretty good. I wonder how extensible, if at all, the core engine is though.
Dreaming on...