Another bit of info:  I believe GM Gagunashvili played this (4. Qc2 0-0 5. Bg5) in the Euro championship just concluded.  As I recall, his opponent didn't play 5...c5, but rather 5...d6.

Thanks for your answer. 
I don't think white must sac a pawn after Bh4 because g5 is too risky and White will take on c3 with the pawn and the position looks like a better version of the Leningrad variation for white. 7. h4 is an intresting option but I wouldn't think Black should be troubled, too.

What about this move? 

In my last game I played ...c5 and my opponent reacted with e3 and I got an equal game and later outplayed him. In the game I didn't know what to do after 

d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 0-0 5.Bg5 c5 6.d5 Line

I think d5 is quite dangerous for black and I don't know what to do. Black can get a Leningrad Nimzo with castling - this should be bad, isn't it?
6.. b5 is perhabs the strongest move but I found only 2 games played with this move and in both black lost!

Agdestein,S (2600) - Stefansson,H (2530) [E32]
Reykjavik zt Reykjavik (8), 1995

1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 0-0 5.Bg5 c5 6.d5 b5 7.dxe6 fxe6 8.cxb5 d5 9.a3 Ba5 10.e3 Nbd7 11.Nf3 Qc7 12.Be2 Ne4 13.Bf4 Bxc3+ 14.bxc3 Qa5 15.Ng5 Nxg5 16.Bxg5 a6 17.e4 axb5 18.exd5 exd5 19.0-0 Bb7 20.Bd3 h6 21.Be7 Rf4 22.Qe2 Qb6 23.Rae1 Rxa3 24.Qh5 d4 25.Bf5 Rxf5 26.Qxf5 Qc6 27.f3 dxc3 28.Rd1 Bc8 29.Rd6 Qb7 30.Rfd1 Ra7 31.Qe6+ Kh8 32.Qg6 Ra6 33.Bf6 gxf6 34.Qe8+ Kg7 35.Rxd7+ 1-0




Khanukov,B (2346) - Chehlov,A (2267) [E32]
Wch Seniors Arco (7), 24.10.2001

1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.Qc2 0-0 5.Bg5 c5 6.d5 b5 7.dxe6 fxe6 8.cxb5 d5 9.a3 Ba5 10.e3 Nbd7 11.Nf3 Bb7 12.Be2 Qe7 13.0-0 Bc7 14.Rad1 Qf7 15.Bh4 h6 16.Bg3 e5 17.Nd2 Qe7 18.e4 d4 19.Bc4+ Kh8 20.Nd5 Nxd5 21.Bxd5 Bxd5 22.exd5 Qd6 23.Qb3 Rab8 24.Ne4 Qg6 25.f3 a6 26.a4 axb5 27.axb5 Rb6 28.Qc4 Bd6 29.Ra1 Rfb8 30.Ra7 Qe8 31.Rfa1 Bf8 32.R1a5 R6b7 33.Rxb7 Rxb7 34.d6 Qb8 35.b4 cxb4 36.Qxb4 Qc8 37.h4 Qc2 38.Kh2 Kh7 39.Ra8 Qd3 40.Rd8 Rxb5 41.Qa4 Nb6 42.Qa2 Nc4 43.Rxf8 Rb2 44.Qxb2 Nxb2 45.d7 1-0



regards Tom