Emulation of any kind reduces performance, I would be surprised if they got all the games to 100% speed.
Sony really screwed you guys when they took away your entire existing library of games. I find it borderline incredible that the only current-gen console with 100% free backwards compatibility with the previous generation was Nintendo. I thought such a feature was an expectation and not even an option in regards to feature cutting to save money. I mean really, the main chip of a PS2 costs what? $50? They just wanted to push the PS3 out and not worry about it because who doesn’t want to keep that old PS2 hooked up?
Keep in mind that PS2 sales have still been extremely high since the PS3 came out. Now that they are finally starting to decline and production is becoming less profitable (???) they could cancel production and focus on their current-gen console only. Saves money, another cost cutting venture.