As far as I'm concerned, there are exactly two capital-letter Events in the world of development-related blogging.
The first, and most well-known, is the epic review that John Siracusa writes for Ars Technica when each new version of OSX is released. Here's his OSX Lion review. These reviews are so anticipated that people train in anticipation of them - via epic training montages.
The second - and my personal favorite, actually, despite my general move away from Windows - is the semiannual list of Windows power tools that Scott Hanselman posts. His 2011 list is now up.
If you do any sort of work on Windows, check it out. Hanselman is one of the most insanely productive and talented Windows developers on the planet. This list is full of battle-tested tools. No fluff. You are guaranteed to find at least one genuinely useful thing you didn't know about before.
At the very least, scan the list and file a few things away in the back of your mind. Even if you don't need anything today you'll know to check it out later when the need arises.