While this is great for humans on the collective level, it kind of sucks for the individual human PC who's stuck being the second-best [whatever] in a party of first-bests of other races.The way I picture it is that, if each of the major D&D races sent out an adventuring party consisting of each of the major classes and they all got together in a tournament to compare their strengths, the humans wouldn't have the best wizard in that tournament, or the best rogue, or the best cleric, or the best fighter - but they'd have the second-best wizard, and the second-best rogue, and the second-best cleric, and the second-best fighter, and while they wouldn't bring home any gold medals, they'd probably win the competition as a whole.
I agree with Li Shenron; I prefer the "more specialties" approach. Whatever you want to specialize in, humans can do that and be competitive with any other race.