I'm exhausted after travel and coaching, but with the final round coming up in a few hours I'll try to get caught up before hitting the hay. To no one's surprise, Magnus Carlsen has clinched clear first in the 2013 Tata Steel Chess Tournament (Group A). His crushing victory in round 12 over Hikaru Nakamura gave him a point and a half lead with a round to go, which means he wins unless the organizers decide to switch to a 3-1-0 format for the last round alone. That gives him a crazy score of 9.5/12, and with a draw in the final round he'll equal Kasparov's great 10/13 from 1999; a win, obviously enough, would break that record.
Levon Aronian defeated Nakamura in round 11 to keep within range (Carlsen drew Wang Hao in that round - and he was in deep, deep, deep trouble) of first, but in round 12 he didn't get much with White against Anish Giri and only drew. Aronian has 8 points, and so does Viswanathan Anand - though he could easily have reached 8.5. He was winning against Hou Yifan in round 11, but was swindled in the endgame and only drew. In round 12, Erwin L'Ami was fine out of the opening with Black, but Anand ground him down and won the endgame.
Hou Yifan had a good pair of rounds. In addition to the swindle against Anand, she defeated Ivan Sokolov in round 12. Another overperforming underdog is Loek van Wely, who bounced back from a loss to Peter Leko (the latter won a nice rook ending) by defeating Fabiano Caruana. Caruana also lost in round 11, crushingly, to Anish Giri, making three losses in a row for him.
You can see the other players' fates in replaying the last two rounds' games, here; I've offered some notes to three of the games. Here are the final round pairings, with player scores in parentheses:
While the drama in Group A has left the building, there's plenty left in groups B and C. Arkadij Naiditsch, Sergei Movsesian and Richard Rapport share the Group B lead with 8 points apiece, and Jan Smeets is just half a point behind. In Group C Sabino Brunello and Fernando Peralta have shared or flip-flopped with the lead all tournament long, and coming into the last round they each have 10 points, a whopping 2.5 points ahead of their closest pursuer.