Possibly the revision is due to the fact that BluZilla mopped the floor with HDDVD, so the price of BluRay tech, which has already fallen fast, will fall even faster, and Sony's earnings will be correspondingly greater.
Also, that $400 price tag is a bit misleading. Sony is selling lots of BC-compatible $500 systems, which are either breakeven or slightly profitable, especially in European markets. They've got plenty of headroom to shave $50 off the PS3 in July and another $50 in October, though my guess is they'll wait and do the full $100 cut in October.
Either way, $299/299EUR is coming this holiday season, guaranteed.