Yeah, I was always waiting for prediction engines to kick into high gear on aggregators, recommending posts, subs, or even filtering comments based on what you seem to like.

They could also harvest data on how often people click through a headline, how long they scroll through a comments page, how long until they move to the next item...

So in addition to having more voting options on an aggregator, I also want a separate aggregator that's purely driven by behavioral data, like average clickthroughs and time on page.