AideRSS filters RSS feeds based on popularity based on comments, posts to del.icio.us etc.
Feedblitz provides RSS to email integration
Dapper.net is another site that lets you manipulate RSS feeds.
But how can you do this inside the enterprise firewall?
You could use Presto from JackBe?
Another alternative that I thought of is to install the Open Source version of SocialText and use the platform to collect RSS feeds and re-purpose those feeds via a wiki page.
Microsoft's SharePoint is not an option if you want to aggregate or filter SharePoint RSS feeds because the RSS feed handler in SharePoint does not handle the authenticated feeds produced by SharePoint.
Campers deciding the Agenda at BarCampRDU earlier today.