I find it interesting that video games like Modern Warfare 2 retail for around $60, whereas movies cost a mere $10 (at least at my local theater). Perhaps we should compare apples to apples, as in units sold versus simply using gross income.
For a film to gross $100 million, it would require 10 million ticket sales. On an opening weekend for a popular film, this is very possible. However, a video game would only need approximately 1.7 million sales to equal this gross income, due to the factor of six difference in price.
This $400 million corresponds to approximately 6.7 million sales, which is slightly less than the opening weekend revenue of many large Hollywood blockbusters. I find it interesting that the numbers are becoming so close for the two media.