Which puzzles me, because I started gaming as a kid with 3rd edition, but nowadays I play 2nd edition AD&D. I won't go as far as to call myself "old school," but there are a lot of things I like about the playstyle, and the older editions in general. I also know two guys my age who play 2nd exclusively, despite starting with 3rd, and will take any opportunity to declare 2nd's superiority.
It's possible that us whippersnappers are just absorbing older gamer's nostalgia; I'm interested in playing older games mostly because of what I've read in the old school blog-o-sphere, and one of the other guys I know started playing 2nd edition when his neighbor gave him four or five boxes of books and miniatures and stuff. But I really do think that they're different games, different enough to be worth investigating.
I used to tease that guy about playing such an obsolete game. I assumed that the differences between 2nd and 3rd, and between 2nd and 1st, and between 1st and OD&D, were mostly a matter of fixing things that were "broken," and making the game more intuitive. That was the intent behind most of the changes, but there's a lot of really interesting stuff that got left behind along the way -- the troupe style of play, campaign-centered (as opposed to character-centered) play, irregular parties, and genre bending, just to name a few ideas that have changed the way I think about D&D, and gaming generally.
(Completely unrelated side note: I think "whippersnapper" is a pretty good term for those young, hip gamers who are getting into the old school scene. But that's just because it would give me an excuse to say "whippersnapper" a lot.)