About January 2010 update

f6 is a Sveshnikov's idea but in the sequence 6...Bd7 7.b4 cxd4 8.cxd4 f6!?

and was also dealed in chesspub update June 2006: 
5.a3 (instead of 5.Nf3) f6!? Juglard-Barsov,Tarbes 2003

Often game can transpose to Tarrasch lines or Advance closed line with c4.

Maybe annoying is: 

7.b4 (L Pospisil vs Dominik Parak, 1995) cxd4 8.cxd4 fxe5 (8...Bd7 Sveshnikov) 9.dxe5 and now 

9...Nh6 (9...a5 10.b5 Bc5?! 11.bxc6! Grujic-Maksimovic,Niska Banja 1996 (Pedersen)) 10.Bd3 Ng4 11.Qe2 Nd4?! 12.Nxd4 Qxd4 13.Bb2 (better than 13.Bb5+ Kf7 14.Bb2 Qf4 15.Qd2 Qxd2 16.Nxd2 unclear)