I've still got a PS2 but my PSX died ages ago. I'm sure it could have been fixed with a simple laser replacement or something, but I was only vaguely aware of such things at the time.
I'm late to the PS3 party, I've only had my 160GB slim since last October, so I'm a little less aware of what's been taken away from each upgrade. The only thing that comes to immediate attention is backwards compatibility for the PS2, but I have a PS2 that's only a couple of years old. And of course, I don't have any PSX games of my own lying about, but the few I have popped in for a moment out of curiosity worked just fine.