The players repeated Game 3 up until move 15, where Anand varied with 15. ... Rg8, anticipating a possible improvement by Kramnik, who chose to sacrifice material in their earlier encounter. For the next 10 or so moves most commentators thought that Kramnik held the better position, but by move 24 Kramnik began to lose the thread of the position. Then on move 29 he grabbed a pawn that was definitely poisoned, and had to resign 7 moves later. Anand's 34th move (Ne3!) was an elegant way to end the game.
So Anand leads 3.5-1.5 after 5 games. In such a short match (12 games) this is already a significant margin, and I would be surprised if Kramnik is able to come back from this. What we may see know is a couple of safe draws before Kramnik tries to mix it up, hoping to force Anand into error. If that strategy fails the end result could be a real blow-out.