This surprised me a bit.
Lately on Digg and elsewhere there has been discussion of the Playstation 3′s availability, especially in comparison to the Wii. At about 6pm today on December 23rd I was at Wal-mart and overheard a man on a cellphone convincing someone it was time to give up on trying to find a Wii. Meanwhile I saw two Playstation 3s sitting on the shelf
Could just be that no one knows or something, but with other reports around, it might just be that some have lost last second interest given that Christmas is 2 days away. Source.
UPDATE: More. Thanks, Ben.