Actually - i have been playing around with building a feed on top of a single torrent - so it would be one torrent per user - and subscribers to the torrent would (hopefully ;)) get a feed of updates
I have always thought that it would be great if the original uploader of a torrent could (securely) modify the torrent so it could have multiple versions, ie if they found one file was corrupt they could update just that file, or add more files (say it was a TV series, they could just keep updating the original torrent with the new episodes). And when you connected to the DHT it could ensure you had the latest version. Of course it would add complexity and I'm not sure how torrent indexing sites would cope but it could be cool.
Signed torrents with versioning.