Douglas Cole also blogged about this. Go read that, too.
Necropraxis put out the results of that OSR survey I linked to a while back.
The comments are where the really interesting discussion is, for me - can a game not be old school, but play old school well?
Of course my answer is yes. I'm playing 4th edition GURPS and Felltower is very much old school. It's inspired by the games I played as a kid running AD&D and by the things I heard about from games earlier. It's a megadungeon crawl with a minimal outside world with a very high body count.
I think that's what D&D5 is, too. It's a new game, and new school in many ways. But it clearly can play old school - and it even as a very playable and interesting megadungeon published for it.
And as a total aside, I find it pretty amusing that more people think Labyrinth Lord is OSR than AD&D 1e is. Heh. I can kind of get it - AD&D 1st edition isn't a revival, renaissance, or resurrection, it's just the old school itself. Yes, there are older games than that, but if the DMG isn't old school gaming, if AD&D is somehow less "old school" than DCC, well, I'm not really sure we're all using the same definition. Which we're almost certainly not. Is an original old school game OSR, or just original? Is it more or less OSR than OSR games? And it's funny to think of people in, say, 1979, lamenting how the hobby had gone all new school with AD&D. Heh. The more things change . . .