When you take into account that the Kinect was released last year during the same time. Kinect went on to sell 8 million units in 60 days making it the fastest selling consumer electronic device ever. These numbers should show how strong the video game industry is performing. Many high demand releases in the same period should do well for GME used games, not shown on the NPD report.
I think the bigger story is the tablets. The ASUS Prime $499 has been sold out online for days. The revenue for hardware this quarter should be huge when the Prime is like selling 5 Wiis. GME also has a propriety tablet controller which should be another high margin item.