Exalead is now displaying an RSS button in results if that particular webpage in the results is RSS enabled.
I guess this is the same as what Yahoo! is doing (only they don’t have a button, they have a hyperlink labelled XML).
Internet news also alludes that you can search via the RSS/XML file format…ie. just return results that are RSS enabled (Yahoo! also does this in its advanced search).
Although I couldn’t find this file format in Exalead.
So in a way both these search engines can be used as an RSS keyword search…Fagan Finder has Yahoo! included in its “search for RSS Feeds.”