We don't. While RSS is a good feature to bring in readers and visitors, we do out best to keep rss out of the search engines. Why? When those pages are found as search results and clicked on, you get the rss feed in your browser which isn't normally a good thing and usually unreadable by the visitor.
It's hard to tell. I don't think I got enough expertise, but I use RSS to know some other things except doing SEO.
RSS is a great way to increase your traffic, but the trick is to create the right rss and promote it in the right place. If you have a good rss, you can have more pages listed in google