Why? They're probably going to be mostly ps2 ports.
Unlike Nintendo who rip off their loyal buyers by forcing them to upgrade every time... the PS3 will be backwards compatible and allow you to play PS1/PS2. Plus they will continue to release games for all 3 formats.
I'm sure Nintendo don't make their consoles not backwards compatible to rip off their customers! If you have an original Playstation, you still have to buy a PS2 to play PS2 games, just as you had to buy a Game Cube to play GC games if you only had an N64.
And since the PS2 uses the same media format as its predecessor, it didn't add any significant cost. Imagine how hideous a console that supported NES / SNES / N64 / GC games would be? It would either have a whole ton of different slots which would be awkward, look horrible and liable to breaking down, or you would have to swap adapters round each time you wanted to play a different format game.
How often do you play PS1 games on your PS2 anyway? I don't think I ever have...
What they ought to do is provide wireless controllers with a detachable power cable in case the batteries run out, or you need extra power for rumble etc. Then you'd get the best of both worlds.
I'm not sure how well this would work, but you could have some kind of docking station to recharge the controllers like the Logitech MX series mice do. If it was well designed and the station was perhaps built into the front of the console it could work really well.
Ahh come on, everyone's got their own opinions of ATI and nVidia...I personally like ATI (I own a Radeon x600). They are in very close competition and ATI has a driver that runs all of their stuff too (Catalyst) so that wasnt really too fair now was it 
I had a Voodoo Banshee, 2 x Voodoo2 (Q2 @ 1024x768!), Voodoo 3 3000. Then I went for the GeForce series right up to the FX 5200. This is one of the biggest pieces of crap I'd ever wasted my hard earned cash on and i would have taken it back if I hadn't bought it 6,000 miles away in the US. I then bought a 9800 Pro and just got my hands on an X800 XT PE because it seemed the best PCI-Express solution.
Both companies are so close in terms of quality, price and features, you could almost flip a coin. Same goes for Intel and AMD these days but that's an entirely different debate.