Of course, Kramnik will no doubt amass an impressive team as well, though unless Vassily Ivanchuk can avoid playing in a tournament for more than two days at a time or Veselin Topalov experience the most amazing change of heart in history, there isn't anyone except Alexander Morozevich who could balance Carlsen in terms of strength. That isn't necessarily the most important factor though. It doesn't hurt, but a team of strong 2600-2700 players with great ideas and camaraderie and a strong work ethic should be able to do the job. Here's my list of possible Kramnik team members:
Peter Svidler: Super strong and very good friends with Kramnik. On the other hand, he's friends with Anand too.
Boris Gelfand: Same pluses as Svidler, and I'm not aware of his being chummy (or hostile to) Anand. Assuming he has the energy and the inclination, he could be a great choice.
Evgeny Bareev: For many years an elite player, a former Kramnik second (in the Kasparov and Leko matches) and good friend of Kramnik's. Drawback: It's evident that he hates the burden of being a second in a world championship match, and he doesn't seem to be playing at the elite level anymore.
Alexander Motylev: Young and strong, and he has worked as a Kramnik second before. I wouldn't be surprised if he's part of the team.
Loek van Wely: A very good theoretician, who seconded Kramnik in Mexico City last year.
Miguel Illescas: He has worked several times as a Kramnik second, and he seemed to make a very great contribution to team morale in Kramnik's earlier matches.
Anyone out there with some other informed guesses?
Returning to the start of this post, about the members of Anand's team: this information comes from a fairly wide-ranging interview with Kramnik in the Russian Sport Express. (That's in Russian, but here's a link to an online translator version of the page - give it a few seconds to work its wonders.) Some of the material will be familiar from other recent interviews, but there's enough that's new to make it worth a couple of minutes of your time.
HT: Chess Today.
Korchnoi is a good example of someone whose understanding of chess far exceeds his playing ability at this time. He refused Keres generous offer to be a second during the Karpov match because he thought it would make him feel inferior.
Kasparov is another example. He hired Dokhoian. Dokhoian is the type of person who would be a better second than player because he is in poor physical condition.
Didn't Svidler and Gelfand help Kramnik in the 2000 match? Kasparov complained in an interview that his opponent had a better team than his.
An unlikely recommendation for Kramnik would be Gata Kamsky. Kamsky surely wouldn't want to second someone he might meet in a match, but he has a long, successful track record against Anand and, unlike many seconds, has some match experience. His style is also more in accordance with VK than, say, Radjabov, who would also be a fun superstar second.
But I doubt that having the strongest player as a second is necessarily what you want. Look at Topalov's success with Chep. as his second.
jdb: Lots of people like Monty Python, but it looks like you were a prescient guesser. Shirov would be an interesting choice, but that would just be piling on! Svidler &Gelfand may have helped Kramnik in 2000, but they weren't seconds. His seconds in that match were Bareev, Lautier and Illescas.
Outis: Unless you think Shirov was stronger than Kasparov - a pretty tough sell - your comment directs us to the answer: working with Kasparov gave Kramnik special insight into...Kasparov. One very concrete way in which that manifested itself, that I believe Kramnik has mentioned somewhere, was that Kasparov didn't consider the Berlin in preparing for Anand.
rdavis: Nowadays, being a second at an event like this means working more or less as a slave on opening prep. If you want to get a great idea of the psychologically claustrophobic life of a second during a world championship match, read Evgeny Bareev's great book From London to Elista (a book very much worth reading for many reasons). About Kamsky: even if he were inclined to work as a second, the fact that he's in the final four for the world championship and playing Topalov about a month after the Anand-Kramnik match makes that impossible. I agree with you (and naisortep) that having the strongest possible second isn't necessary, but we shouldn't exaggerate the other way either: Cheparinov is a very strong player himself.
For seconds Morezevich and Svidler would be good of course. Ivanchuk might do it if he is promised a match after the topalov/kamsky winner gets their turn. if topalov wins, then i have doubts about him getting a title match against kramnik if he wins. Vlad will clearly expect considerable concessions before he even cosiders that mess again. [Snip!]
efe: It's way more than "some novelties" - the creative work they'll do with their seconds will put them ahead of their peers for months, even years in some lines. The work has already begun, but it becomes a practically round the clock operation once the match starts. One reason for keeping the seconds secret, if possible, is that if I know that grandmaster X is a specialist in openings A, B and C, then I may at least have an idea of what's coming.
Kevin: I'm quite sure that the Sveshnikov won't come as a surprise to Anand. If you and I both thought of it, the odds of Anand not thinking of it are 0. As for Ivanchuk, there aren't any such promises to be made: FIDE's cycles are in place, and there aren't going to be any ad hoc matches determined by players outside the cycle. As for the last sentence of your post (to be deleted momentarily), let's not go in that direction, especially since it's off-topic. (Granted, Topalov's shenanigans in 2006 encourage that sort of comment, but we can rise about it!)