It would be a huge mistake if they did, but I don't believe that Sony could produce the required supplies for such a launch. The PS2 and PSP were both in very limied supply at launch, so it seems unreasonable to expect them to not only have enough systems for a launch in a single region, but to be able to supply all 3 major regions at once.
But even if they could, launching at the absolute slowest time for system and game sales in both the US and Europe would be just begging for a lackluster launch. Sony sells over a million consoles per month in America alone during the holidays, but is lucky to break 200k sold in a month during the Spring, so why would they want to launch in the Spring?
Of course, with their history of supply problems, maybe it would be better to launch at a time where the system will be in low demand.