Of course it isn't. Wii is outselling Xbox 360 and is expanding the market. Therefore it's having a bigger impact on the games industry.
As much as I love Xbox 360 (and Xbox Live) I'd actually argue that Microsoft is a fairly stupid company, what with the decision to sell a console without a hard drive, the hardware problems they've had, and of course still charging £40 a year for Live when the PSN does it for free and I believe on dedicated servers.