FeedBurner is the only service (that I know of) that will re-publish a blogs feed in order to get feed stats. Being such a great service, many users use it only to figure out how many readers their blogs have. However, FeedFlare is a great addition to any FeedBurner feed as it builds interaction and social media links into each post.
FeedFlare allows publishers to easily build “interactivity” into the content they create, making it simple for subscribers to tag, email or share their content with others. Publishers can include a variety of services including a live display of the number of comments to each post, the ability to email the author directly and show the number of blogs that link to their item.