Well most mainstream websites are unaware of Vgchartz, and professional tracking agencies (the guys who actually get paid), charge money for their data, so it won't be official for a while yet...
But this thread is only about USA sales, where Wii remains at least 6+ months away from pulling ahead of lifetime Xbox 360 sales...so I don't know why you put that question here?
People are difficult to govern because they have too much knowledge.
When there are more laws, there are more criminals.
- Lao Tzu