Domdaniel: This line, with 6.Nxd5 Qxd5, is a bit dubious. It has been tried before, but Black seems to equalize comfortably, and White never generates much play against c5 or e5.
Better, and far more popular, is the obvious 6.Bg2, when Black could continue Rubinstein-style with 6...Nc7, or with something like 6...e6 7.0-0 Be7 8.d4 0-0 etc.
Despite the ugly d3 pawn, White only begins to lose this game with 22.h4 and the strange Qg2-h3 maneuver that followed. He could still have played 22.d4, liquidating what's left of the centre, with a fair chance of a draw.
Maybe 22.h4 was a try for a win, but the position doesn't allow it. Once Black has the dominant Bishop, mopping up the queenside and hitting f2, White collapses.