It's worth noting the Valhalla 360 chipsets are due next year, so we're probably looking at a 360 price drop at the end of August/September as usual.
Since Sony has ruled out a 2008 price drop and it seems unlikely they will drop before the end of their fiscal year, Sony have between April 1st 2009 - September to bring the ball back in their court before they face the brutality of the 360s competitive price tag.