I just remembered an instance when Sony admitted that the PS3 is competing with the Wii...
Anyone remember when Howard Stringer attributed a spike in PS3 sales due to a price cut and Nintendo's inabilities to produce enough Wiis? That would suggest that he believes that the lack of Wiis on shelves means people would pick up a PS3 instead.
I'm sure I saw this on Next Gen, but I'm too lazy to look it up right now (maybe later). Also, my apologies if someone already mentioned this.