That's because it's Sony and the mainstream media will perpetuate (sp) the idea that if Sony does it, then it was either first done by Sony, or done better. I for one have no immediate desire for a PSP, no games say "Buy me." and the idea of the connectivity between the PSP and PS2 and possibly PS3 is that the games will be nothing short of the same exact game, where you can transfer game data from one system to the other and pick up where you left off in either. I find that more lazy than Nintendo porting old(er) games from their previous systems, because they are no perpetuating the idea that you are buying something new and different.
So what I am saying is, basically "Nintendo did it first, but Sony is going to get the credit for it because they own the mainstream media"