Feed Mix
Feed Mix is an RSS editor, which is powerful enough for RSS gurus yet refreshingly easy for RSS first timers. It lets you create, edit and publish the unlimited number of RSS feeds and podcasts. Unique to Feed Mix is its ability to create a new RSS feed or a podcast from several existing feeds. ... You should specify which news from the selected RSS feeds you would like to see in your new RSS feed, and all the mixing job is done by Feed Mix. ... You click on the "New Project" button to create a new RSS feed, select the source RSS feeds and add them to Feed Mix.
http://www.extralabs.net/FeedMixSetup.exe - 2Mb - Download - Screenshot

Propaganda
The easiest way to create high-quality podcast recordings. Propaganda software is a powerful tool that you can use to create commercial-quality podcast shows with a minimum of effort. Whether it's voice recordings, music or sound effects, Propaganda can record it, import it, and store it. ... You can mix voice interviews over background music for commercial-quality results. ... Propaganda will upload your completed podcast to your web site, with full RSS, XML and HTML support. ... Propanda also handles music and sound effects as easily as spoken-word recordings.
http://dl4.mixmeister.com/016/prpgdemoinst.exe - 15Mb - Download - Screenshot