Console Post AddendumJoystiq is reporting that during Gamestop's earnings conference call, CEO Paul Raines said this:
Supply on hardware was a continuing challenge this quarter, as on an average daily basis, our U.S. stores were out of stock for the PS3 for 80 percent of the time and were out of stock for Wii 50 percent of the time.
This lends credence to the notion that both the Wii and PS3 are supply constrained right now. To what degree this is affecting sales is not determined.
I'd add Sony's stupid comment about demand being "incredibly high" when it's not high at all and they're only forecasting 15% growth this year, but you can just fill in the blanks yourself.