Feedburner gives some context to the recent changes from google reader and how they affect your subscriber numbers. It's worth a read if that's an important metric for you FeedBurner's View of the Feed Market

While it's always encouraging to see feed subscription numbers go up these subscription numbers in a vacuum only tell part of the story. Equally important is the extent to which people are reading feeds and interacting with them. In today's post we'll take a look at one aspect of the feed aggregator market - the web-based aggregators - and draw some conclusions about how audiences are consuming content in new and different ways.