mmorpgs are something that are best left to the PC/MAC imo, just like RTS and to a point FPS. It, at this point doesnt seem plausable for it to be on a console, unless they become extremely computer like in the next gen. I think that a GTA MMORPG spin off would most certainly work, and could start a new "brand" of mmorpg, getting away from the scifi/fantasy driven games of today. I think that it could be a huge success, with all sorts of "rated M" content to drive the game, but i just dont see that happening on a PS# or xbox.

edit: and i dont forsee GTA going futuristic anytime soon, i would imagine there next move would be either overseas, or two a different decade again. GTA: Rio desionaire, GTA: Hong Kong, GTA: Moscow, GTA: Paris, GTA:London, are some that come to mind off hand as possible spin offs. If you are talking time periods these all jump to the front of my thinking GTA:1920' (mafia was big, p[rohibition was around, enough old cars, and guns to go around.) GTA 1970's(disco, and cocaine). They still have more than enough material to work with to keep cranking out games...