The white king is too exposed, and the pin  along the g-file is more than nasty.
1. e2e4  1... e7e5  2. g1f3  2... b8c6  3. f1c4  3... f8c5  4. c2c3  4... g8f6  5. d2d3  5... e8g8  6. e1g1  6... d7d5 This active  approach against the Italian has gained more and more attention lately,  mainly thanks to the efforts of the likes of Aronian, So and Nakamura. 7. e4d5  7... f6d5  8. f1e1  8... c8g4 Active defense of the center. 9. h2h3  9... g4h5  10. b1d2  10... d5b6  11. c4b3 Previously, White was mainly putting more pressure  against the black center with 11.Bb5. 11... g8h8 Once again a very  concrete, aggressive move by Kosteniuk. She is ready for the kingside  push. This was also the Russian's first long thought, almost a quarter of  an hour spent on her clock. 12. d2e4  12... c5d6  13. g2g4 The first long deliberation by Muzychuk. She needs to  stop the black f-pawn. In fact, White does want to exploit the f5-square  for her knight, but this is easier said than done. 13... h5g6  14. e4g3  14... b6d7  15. b3c2 All eyes on the f5-square! 15... a7a5 Kosteniuk  expands on the queenside just like Mamedyarov did against Anand. 16. h3h4  16... h7h6  17. h4h5 Muzychuk is also immensely aggressive on the kingside. 17... g6h7  18. g4g5 Obvious, but White is about to face a nasty surprise. 18... f7f5 The game is opened in Black's favor. 19. g5h6  19... g7h6  20. c1h6 