RSS to MARC

I stumbled on an interesting idea through a longish clickpath which led me to Cataloging the blogosphere in Infomancy. In a nutshell, Christopher Harris proposes converting RSS items into MARC records using XSLT transforms. Which is a pretty neat idea.
I’m inferring from Christopher’s post that this would be a valuable tool for selected, probably edited, sources — he mentions the Librarians’ Index to the Internet in particular as a good source; and David Bigwood of Catalogablog adds the Scout Report as another possible input. And I’ll suggest the Internet Public Library as another source of vetted content for generating reference sites that other libraries might consider adding to their own catalogs.
How many libraries, I wonder, are currently adding web resources to their catalogs? And how many of those could use an automatically generated Choice combined with the MARC record for the resource? A one-click “add to my catalog” resource for librarians, complete with MARC data.