...that the winner's identity will be known by May 13 at the latest. Before offering my prediction, let me offer some general comments and summarize other predictions I've seen.
First, I think the first player to win a game will almost definitely be the winner of the match, especially if they "consolidate" the victory (i.e. not lose the advantage in the next game). I think Topalov is more resilient than Anand - or perhaps I should say that Anand is less resilient than Topalov. If Anand falls behind, I'm not sure how he'll do in a situation where he needs to claw his way back. On the other hand, I believe that Anand's best chess is better than Topalov's, so if Anand starts well and gets his confidence going, I think it'll be like the Anand-Kramnik match, where Topalov will have to fight to avoid getting flattened.
Second, Anand generally seems to be the favorite, not only in terms of rooting interest but also in people's predictions. Only the Carlsen-Aronian-Gelfand-Ivanchuk group seemed to stick resolutely to a 50-50 evaluation. There's often wisdom in numbers, but these four know them about as well as anyone and it would be hard to find anyone better suited to judge than they are.
Third, obviously, any predictions based on their chess are in danger of incompleteness, given the possibility of a Son of Toiletgate protest. If that kind of nonsense happens again, FIDE President Kirsan Iljumzhinov should punish the miscreants severely. How it will effect the match is something I don't know, and for now let's be optimistic and assume it's not a real possibility.
So it's time to predict. As I said, I think the first winner will probably win the match - especially if it's Anand - and I'll add a second conditional prediction as well: if Anand plays the Queen's Indian and holds with it, I'm very optimistic about his chances. I really don't see Topalov outplaying Anand in games where he gets nothing from the opening. Also, while Topalov is +1 in their slow time control games, Anand has a big advantage against him in faster time controls (as he does against almost everyone). So 6-6 almost definitely means Anand wins. Overall, I think Anand has the bigger game, so unless there are shenanigans I'm going with Anand to win 6.5-4.5.