I don't think number 2 is true, even though a lot of DC fans wouild like to believe that.
The PS2 may be more powerful, but it might not be powerful -enough- to correctly emulate a DC at decent speeds.
As far as the games, IMO Sega and Sony would both benefit from such an emulator, I could even see an official one released by Sega. Why? Because Sega could sell more games, without doing any more work (other than implementing the emu.) And all of a sudden Sony would have another couple hundred games for it's PS2 platform, above and beyond the 500+ PS1 games, and however many PS2 games there are now. In the console wars, such an occurence could really tilt the scales in Sony's favor.
It's nice to dream anyway. I realize that it's highly unlikely that it would ever come true.