If they do make another one I want them to finish of this storyline or even make a fourth with the after math of everything, but I'm getting ahead of myself. If they do want to make an mmo I wouldn't mind it as long as it looked something like this:
You have your KIII and the whole regular game like we had in K1 and K2, however I wouldn't mind a whole NWN2 thing where you could make you own maps and crap and play with other peeps online or on a lan whether this be your modules or the regular game. Now for an MMO it could just be in a different slot that says MMO(yes real original) and it would start with the events that have just happened in the regular KIII, something like this.
Oh and also the MMO would be free online play but this is LA so I doubt that.