Two million was the original number, with an equal shipment to both North America and Japan (the European release has been pushed back to March), but various problems on the eve of release seem to have cut that number down to size.
"The honest answer is it's [our worldwide shipment numbers] more of a target," said Sony Computer Entertainment America co-chairman Jack Tretton. "Clearly we've had production issues."
Launch numbers seem to confirm that that Sony will not meet its goal (and really, how often do they?). 400k units are slated to be available on launch day in North America while a paltry 100k is headed to the company's home turf. This does leave another month-and-a-half to increase those numbers, but it is unlikely that they'll reach the "target" in the US, let alone Japan.