No-one: Don\'t promise that the PS3 won\'t be backwards compatible. Personally, if it\'s easy and cheap to implement, I don\'t see why they wouldn\'t! Backwards compatibility is one of the greatest features ANY system can have. I still get out the ol\' sega Genesis once in a while, but I would have been willing to pay 30-40 bucks more for the saturn or dreamcast (*had they used the same media, for instance*) to have them backwards compatible. The truly great games never die - I still play Phantasy Star II, Phantasy Star IV, Super Metroid (SNES), Blaster Master (NES).
If they don\'t make the PS3 backwards compatible, it means people who occasionaly want to play PSone games have to plug in their old PSone or PS2.... I think many would be willing to pay a small amount more for full backwards compatibility (ie, 15-25 USD).