It seems like everyone has a blog these days. The MSDN blog aggregator, I don't know what else to call it, might have been a place you could go, at one time, to find relevent blogs written by Microsoft employees. However, these days there are so many bloggers you have to wade through all kinds of stuff you don't care about to find just one interesting post. The Microsoft Communities blog portal has come to the rescue. This portal allows you to search Microsoft blogs or posts based on categories. Better, if you find a category you want to monitor, it will give you an RSS feed for that category.
Didn't find a category you were looking for? Then request that one be added. Once the category is created you'll have a bit of a wait though. The system depends on bloggers to add their posts or blogs to the categories manually. Try the drivers category for example. It didn't exist until a few days ago. I requested it and added my blog. So far it appears to be the only blog in that category. I know people are using this because I'm getting all kinds of referrals from it.