Alternate title: Skydasher and the world of tomorrow.
I managed to get my hands on a short video of an online aggregator / portal / newspaper of the future:
The credit goes to an anonymous source. The description I was given explains that the media center component gets enclosures coming in from various RSS feeds, and sorts them into the appropriate section based on the type of media.
The UI, by the way, is a DHTML interface.
The features demo'd certainly look interesting, but I'd be more interested in an upstream interface where editors can tailor, sort, and categorize incoming feed items into more digestable feeds for the mass market.
If you're thinking of building something like this from scratch...well, the competition is way ahead of you. But consider using open source as the basis for extending aggregator functionality.