My interest in this was sparked after seeing the game Yu Shaoteng vs Le Quang Liem annonated in the June update. I found it  quite disappointing that noone seemed interested in discussing it(unless I missed something). Most seem to believe it just drops a pawn, which I find strange considering that in other lines black is willing to sac it. At the end of the day, it's trading a pawn for a file against the enemy king.

I toyed around with a bit and I hope others will contribute their ideas, as it isn't ready to refute 12. Kb1 just yet.

Here is the aforementioned game

[Event "8th Asian Continental Chess Championship"]
[Site "Subic Bay Free Port"]
[Date "2009.05.15"]
[EventDate "2009.05.13"]
[Round "3.5"]
[Result "0-1"]
[White "Yu Shaoteng"]
[Black "Le Quang Liem"]
[ECO "B78"]
[WhiteElo "2504"]
[BlackElo "2591"]
[PlyCount "80"]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 g6 6. Be3 Bg7
7. f3 O-O 8. Qd2 Nc6 9. Bc4 Bd7 10. O-O-O Ne5 11. Bb3 Rc8
12. Kb1 b5 13. Ndxb5 a6 14. Nd4 Nc4 15. Bxc4 Rxc4 16. h4 Qb8
17. Nde2 Rfc8 18. Bd4 h5 19. Rc1 Rb4 20. b3 Rxd4 21. Nxd4 Qb4
22. Nde2 Ne8 23. e5 Qa5 24. Ne4 Qxe5 25. c3 Bf5 26. Kb2 Bxe4
27. fxe4 Qxe4 28. g3 Nf6 29. Rhd1 Qb7 30. Qd3 d5 31. Kb1 e6
32. c4 Ng4 33. cxd5 Nf2 34. Qf3 Nxd1 35. Rxd1 a5 36. Qh1 Qb5
37. Qf3 a4 38. Qd3 Qa5 39. Qd2 Qb6 40. Qd3 axb3 0-1

In that game, white lunged forward with 16. h4. Black brought the queen to the b file, doubled rooks on the c file, made play and went on to win.

However, if white plays 16. g4 instead, then it seems quite difficult to prevent g5, kicking the knight and then Nd5, targetting the e7 pawn, making it very hard for he queen and f8 rook to move.
16...Be6 to take away the d5 square seems too slow as white can roll forward with either h4 or even e5, ie 17. h4 Qb8 18. h5 Rfc8 19. Ka1 freeing himself from the pin and now white seems ready to bust open the kingside while black barely has any threats worthy of consideration. This led me to the idea of trading bishop for knight.

After 13...Bxb5 14. Nxb5 instead, the difference now is that there is one less piece on the long diagonal. Now after 14...a6 15. Nc3 Nc4 16. Bxc4 Rxc4, 17. g4 doesn't quite work since black plays Qb8 and his counterplay is coming fast. White can try 17. e5 instead, to exploit the pin along the d file and closing down the diagonal. After 17...Nd7 white will probably want to play f4 to keep it closed rather than exd6. Unfortunately, Qb8 runs into Nd5 again, making it hard to double rooks on the c file.
It's also possible to retreat the knight to e8 instead, which would allow the queen to defend e7 from the seventh rank, ie 17...Ne8 18. f4 Qb8 19. Nd5 Qb7.
Or let go of it with 19...dxe5. Both kind of defeat the purpose though, since the f8 rook will be too slow joining the attack, if ever.
White might also try 17...Ne8 18. Bh6 in which case I wonder how viable Bxe5 would be, giving away a rook for the enemy dark squared bishop.

Last but not least, white can play 15. Nd4 or 15.Na3 instead. On d4 though white doesn't have Nd5 anymore so black will probably achieve his desired setup. On a3 however, white prevents Nc4 and having traded away the light squared bishop, it's not easy to make a plan.