In the US, there have been three releases of the Playstation 3:
The original 60GB version had hardware compatibility with PS2 games -- they effectively had all the chips from a PS2 along with the new PS3 chips. Games should work fine on that model, but it's been discontinued for a while.
The 80GB model has a software emulator for the PS2 installed. This means that it will play many PS2 games, but they may not look exactly like the original hardware and there could be glitches. This model is still available for sale.
The newest PS3 has a 40GB hard drive and is less expensive. However, Sony completely removed PS2 compatibility for this unit, so the older games won't play on it at all.
There are rumors that the 80GB unit will soon be replaced by a 120GB version and that one will also drop the compatibility mode. If PS2 games are important to you and you want to play them faithfully on the new hardware, getting a used 60GB model is probably your best bet. Good luck!
no
Yes
No PS3 games do not play on a PS2
You Can Turn Them Back
No, PlayStation2 games can not be played on PlayStation3.
No, not on the last console made. But you can play to almost all your old PS1 games.
No, but the PlayStation3 does
yes it can. (if you got it, like when it first came out)
Only the ones redesigned for the PS3 and sold at the Playstation Store or on Discs saying PS3. The PS3 slim does not play any PS2 games
depends on the model of ps3 heres a chart if you need help http://en.wikipedia.org/wiki/PlayStation_3
Yes. Playstation2 Playstation3 Xbox 360
yes
Yes it can