Just upgraded News to 4.0.1 and get the following:

Feed 'https://sharepoint.douglasesd.k12.or.us/NetworkServices/_layouts/listfeed.aspx?List=%7BFDBDA648%2D5E56%2D43A9%2DBBC6%2DBA9BBA3D9A39%7D#' could not be loaded. Error: The required attribute 'length' is missing.

This list is from a Sharepoint RSS. I'm using the default XSL.

Ideas on a fix?

More specifically, this feed is failing due to the enclosure element missing a required attribute 'length'.  The default.xsl would not display this element anyway, but it does bring up a security issue that many do not consider when using newsfeeds.  If you bring that feed up in a browser like IE, you'll see the element is named, owsvrr.dll and links to a URL.  In this particular case, I would not be displaying this information, as I don't know what that dll is going to do, or know whether I trust the link to it.

Now, this may in fact be a trusted item and link, but most would not know that for sure.  My caution is to know your feed source before presenting it on your public site, otherwise you could open up security breeches and issues.  On another level, even allowing display of HTML from a news feed should be done with the same caution.

You cannot always trust a news source, just because it's out there.  I'm just saying...