It will be a close race between Roger, Tiger and Michael, that's for sure.
If Michael wins the F1 Championship, it would be a quite incredible come-from-behind win in a very tight dual between him and Alonso. Also, since it's Michael last season, the win would be even more dramatic. (That last race in China was pure Schumacher/Ferrari genius.) Therefore, he'll probably grab the Laureus, albeit by a small margin. Like it or not, I think some journalists will vote based on feelings.