Sony does what Nintendon't? That's the general sentiment from a brief interview that PlayStation chief Jack Tretton gave to Fortune this week, in which he talked up Sony's strengths and played down (some may even say belittled) its competitors, and Nintendo in particular. That began with the relatively tame assertion that Sony's decision to go high-end with PlayStation 3 is just now beginning to pay off while the other consoles are "starting to run out of steam," before he took aim at Nintendo's handheld business. According to Tretton, Nintendo's handhelds all offer what he calls a "Game Boy experience," something that's great as a "babysitting tool," but that "no self-respecting twenty-something i