From Sony's perspective it's a win-win (kinda). The $500 model makes Sony lose about $70-$80 more per unit due to the $100 price drop, despite no significant decrease in price to make (HDs cost a bit to make, but increasing the storage capacity is very cheap to do). Therefore, if Sony can make more money by focusing on the $600 model, expecially if demand is primarily on the 60gb model, then they are golden. IMO, after hearing about the 2 models at E3 last year, I was very suspicious. I think Sony did the $500 model as a knee-jerk reaction to the reception of the Core 360 (which as far as I know has done well). There's a big difference between the $500/$600 PS3 as opposed to the $300/$400 360. On the PS3, you get the smaller HD which is fine, but it doesnt have HDMI or the mem card reader. At any rate, its a win for Sony.
Back from the dead, I'm afraid.