HEre's my response to some of the above threads:
Valiant: PS4? Not likely on shelves for another 7 to 9 years at best. PS2 was around, what, 10 years before PS3? They make these things to go way into the future, that;s why PS3 got off to the slow start: ahead of its time. Now looking back 18 months, you can see that.
The 60g actually had hardware for backwards compatibility. That's why it's 100 percent compatible with PS2. The 80G has a chip, but they activate all the most popular games for that. So, you could say that basically any game you'd WANT to play, chances are it will work. check the link in Cochise's response to see if a specific title is compatible. Also, as new games come out they add them through system updates.
As far as another price drop is concerned? I wouldn't hold my breath. They already dropped them each $100, and the 60G was never reduced in price after it was discontinued, so even if they come out with new versions, I would not think the 40/80G will be dropped to clear them out. THe margins on consoles are not very high.