I don't think it's some straight CMS. It's creating summary and story pages from different topical feeds. Also pulling in photo and video feeds from Flickr and YouTube. And the guy is running thousands of sites with the exact same layout, just different colors and niches. So...I was wondering if this is something he's developed on his own and just duplicated many times, or if this is part of some automated tool that's available. All indications lean toward the former.
Since the majority of the sites I checked all operate on the same server, it seems very reasonable that he is using one CMS package with plug-ins for the additional features. He offers his domains for sale, just contact him and ask about the site.