Blogger Comments Feed

Now blogger (beta) has feeds for comments and comments per post. Check more on the feature here

The links for the feeds look like
Post feed - http://name.blogspot.com/feeds/posts/full
Comment feed - http://name.blogspot.com/feeds/comments/full
Per-post comment feed - http://name.blogspot.com/feeds/comments/full/post-id

Help on Blogger beta new features are here