John, while I remember my gaming group talking about Twilight: 2000, we took a very cyncial view of it, especially after we saw the post-apocalyptic Britain sourcebook, which, if I recall correctly, had something called the Royal Army wandering around.
You’re right about Grognardia, though, which is probably the best of the Old School dungeoneering blogs. I’d also recommend Chgowiz’s Old Guy RPG Blog and the splendidly-named Society of Torch, Pole and Rope. I’d be remiss not to mention here my own, sporadically-updated, blog, The Rune Under Water. I’ve just put up a review of the best RPG core rules I’ve ever seen, Mongoose’s Runequest II, which might be of interest to some.