I guess anything is possible really. I can see Kimi going back to McLaren, and I don't think that will be counter productive to either Kimi nor McLaren. McLaren need a quick driver, Kimi would want to be in a championship winning team, which I don't think people can debate McLaren's history definetley proves that.
Of course if he does he will have to deal with Hamilton, which I don't think will bother Kimi too much... DC didn't bother him, nor JPM, nor Massa, and he was apparently joining Ferrari regardless of wether Schumacher was staying or retiring. So in that respect I don't think Kimi really cares too much who his team mate is, I think so he is only interested in himself doing the best what he can.
On the other hand, I think he has the highest probability to stay at Ferrari. After all, he is contracted for 2010 there. If he continues to put in stellar performances like he did from Budapest onwards, then I don't see a reason why Ferrari would want to give him the axe. Plus it depends on what McLaren are going to do also. Its no doubt Heikki needs to string some stellar performances together if he wants to stay at McLaren, but I think he can do that, and possibly a GP win before seasons end.
@010010011010 ... you wouldn't happen to be a fan of Ayreon or any other Arjen Lucassen's projects???