Look at this chart from 11/4/06-1/1/08. There has to be more to the shortage than "unexpected demand". While the sales are better in 07's holiday, they're not better enough to warrant a shortage.
Changing factory lines? Retrofitting RRoD fixes? New SKUs? Dunno, but blaming the holiday season makes no sense.
I hate to tell you this, but it is not very hard at all to find an Xbox360 around here... so maybe the bad sales are, the later adopters are going with PS3. Right now the Brand is the best thing the PS3 has going for it(and the blu- ray win)
add me, the more the merrier.