Kramnik's threats are far more serious than they seem.
1. d2d4  1... g8f6  2. c2c4  2... e7e6  3. g1f3  3... d7d5  4. b1c3  4... b8d7  5. c4d5  5... e6d5  6. c1g5  6... c7c6 The solid Carlsbad. 7. d1c2  7... h7h6  8. g5h4  8... f8e7  9. e2e3  9... e8g8  10. f1d3  10... f8e8  11. e1g1  11... f6e4  12. d3e4  12... e7h4  13. e4h7  13... g8h8  14. f3h4  14... d8h4  15. h7d3  15... h4e7  16. a1b1 Leko is preparing the minority attack. 16... a7a5 The normal reaction that not only slows down White but also  swaps a potentially weak a-pawn and opens a file for the black rooks. 17. c3a4 A logical move and a novelty. 17... h8g8  18. f1c1 Supporting the knight for the battle for the c5-spot. 18... e7d6  19. a2a3  19... g7g6  20. h2h3 It is not very obvious how valuable this  prophylaxis is. In fact, later it appears that... but better wait and see.  20... g8g7  21. c2c3  21... h6h5 Kramnik expands on "his" flank. 22. b1a1  22... d6f6  23. b2b4  23... a5b4  24. a3b4  24... f6g5  25. g1f1 The king leaves the danger zone, as the pin creates the constant  threat of a bishop capture on h3. 25... d7f6 The black pieces are quite active, and various tricks start  to pop up. 26. c3c2 Away from the knight forks.