The knight development on e2 was Kasparov's favorite. White can wait by playing 8.Qc2 before deciding where the knight goes, or he can also play 8.Nf3.
1. d2d4  1... d7d5  2. c2c4  2... e7e6  3. b1c3  3... g8f6  4. c4d5  4... e6d5  5. c1g5  5... f8e7  6. e2e3  6... c7c6  7. f1d3  7... b8d7 