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Carlsen continued with 10.Qc2. According to Vigorito in "Challenging the Nimzo-Indian" 10.Qd3 is the main line, here is what he has to say about Carlsen's move:

<b) 10.Qc2 This is less logical because it gives up control of d5. Black has not had many difficulties here. A couple of examples:

b1) 10...h6 11.Bh4 c5 12.dxc5 bxc5 13.Nc3 d5 14.O-O-O Qb6 gave Black good play in Kacheishvili - J. Polgar, Batumi 1999.

When White plays 19 f3 to defend the e4 pawn, the reply 19..Nh5 removes White's bishop pair, because the White QB is tied to the h2-b8 diagonal in order to pin the e5 pawn which attacks White's R on d4. This suggests that one alternative to 19 f3 is to prepare f3 by 19 Rd2 so that ...Nh5 in reply to f3 can be answered by withdrawing the White QB by Bf2.

It may be that instead of 25 Qd3, 25 Qb3 Be6 26 Nd5 Bxd5 27 exd5 Qd6 28 Bb5 Rc5 29 Bc6 will gain some advantage. With 33 Bxb5 White has attained what Leonard Barden has called the Fischer ending, with a Rook and Bishop against a Rook and Knight. Black has a difficult ending to defend, if he can do it at all.

Instead of 34 Ba6, 34 Bc4 obstructs Black's Rook and prepares to develop White's King eg to e3 followed by f4