That's modern chess for you: the players reeled off 20+ moves of home prep, Viswanathan Anand seemed to forget something in a super-sharp position, and was promptly massacred by Veselin Topalov: 1-0, 30.
Anand played the Grünfeld Defense, and that's a bit of a surprise. There's certainly nothing wrong with that opening...well, not too much wrong with it, but it's not one Anand has a great deal of experience with. Prior to using it three times against Leko (not exactly a Topalov clone) in a rapid match last year, he hadn't played it since 1998. Further, it seems to play to Topalov's strengths in preparation and attack. Given that Anand had never braved the Semi-Slav against Topalov, though he uses it regularly against most of the other top players, I'd have thought this would be off limits here as well.
That said, Black seems to be okay after 23...Bd7 in today's game, but I wouldn't be surprised if there are some further depths to be plumbed in this area. As it was, Anand either forgot his preparation or reacted very badly to a surprise (though Topalov hadn't done anything by that point that could plausibly have been missed by their preparation), and simply blundered with 23...Kf7. The only real drama was whether Topalov would find (or remember) 24.Nxf6, and when he did it was just a matter of how long Anand would play on.
A lousy start for Anand, but Kramnik won game 1 against both Leko and Topalov and still managed to fall behind in both matches. So there's lots of chess to be played, and we must see tomorrow how Topalov fares with the Black pieces before drawing our first, provisional conclusions. (We'll post on this topic later today.)
For now, here's today's game, with my commentary.