There are a lot of RPG blogs on the Internet, but two in particular stand out, in my opinion.
Kobold Quarterly is a Dragon-style magazine with a website full of new content. KQ frequently publishes articles to its website when there isn’t enough room in the print edition.
The latest interesting article at KQ is I Was a Gen Con Spy For TSR, an article from a TSR employee who was employed to spy on Gary Gygax at Gencon.
Critical Hits is one of the longest-running major D&D blogs. It has acquired some very well-known writers in the past year, including former WotC employee Chris Sims and Chatty DM from Musings of the Chatty DM. Just yesterday they acquired Logan Bonner, a recent WotC layoff who worked on D&D 4th edition.