The immediate 8.d4-d5 is becoming the main line according to my Megabase.
1. d2d4  1... g7g6  2. e2e4  2... d7d6  3. g1f3  3... g8f6  4. b1c3  4... f8g7  5. f1e2  5... e8g8  6. e1g1  6... a7a6 A must win situation, and Carlsen avoids the main theoretical lines. 7. a2a4  7... b8c6 