That would be some major tweaking. I could see this as an undergound movement to hack in multiplayer to games that don't come with it. Pretty sweet.
Sounds like a hell of a lot of work, very complicated, and possibly not very feasible with the structure of the game... might introduce a lot of lag, graphical and network, et cetera. Besides, things like balance might be so far off that the game might not be all that good.
If they can manage it, that's great, but I'm skeptical as to the feasability of the endeavor... and skeptical that the result will be more than just a "well, that's kinda neat."