Why should we buy PlayStation 3 if PS2 is good enough?
This is a good question. I can say that I would buy a PS3 if it wouldn't be so expensive. I would buy a good PC for the price that they're offering. And PS3 isn't as good as a good computer.
You can play on PS3 only the games that you have bought. On PC you can play many online-games though.
If PS3, why then?
3.2 GHz Cell Broadband Engine with 1 PPE & 7 SPEs
Enormous 3.2 GHz CPU! Even my PC doesn't got that! But even if PS3 got a huge CPU, I would buy X box 360, because it's cheaper and has many good games that PS3 doesn't got.
I think that even if PS3 is the seventh generation or so, PS2 is much better and will be sold for some years.
So: SAY NO TO THE PS3