I agree, MMORPG aint gonna happen, buts its nice to dream. Nintendo have already said they will not be persuing that route. But the hardware is there, and with the lifespan of current gen consoles, I would not be surprised if a third party developer released one eventually.
CoD4 giving the Wii a wideberth is not on. Theres no excuse for that. Although Activision have given the rights for CoD5 to Infinity Ward for the Xbox and PS3 versions (Infinity Ward made CoD4), the Wii version is being given the Treyarch treatment, the same people who brought CoD3 to the Wii. So expect more of the same from them.
IMO, what the Wii needs now is a decent racer, with proper online play similar to what EA did with EA Nation. I know Mario Kart will be awesome but I think something like a Project Gothem type of game would really work, shit, i would even settle for Prostreet if it was online.