Hyperlink hierzo:http://www.sharepointu.com/forums/p/240/11244.aspx

Once you have the XSL file in place, and have a URL for the RSS feed you want to add, then all you have to do is add the XML web part and configure it. Put the RSS Feed URL in the field for “XML Link”, and put the path to the XSL file you created in the field for “XSL Link”. If your XSL document is correct, then you’re done.

Nog meer RSS feedreader webparts:
http://www.smilinggoat.net/
http://www.codeplex.com/FeedReader