@scribu Yeah, they should implement a function that takes time into account. Like this:
http://www.evanmiller.org/rank-hotness-with-newtons-law-of-cooling.html

I thought about turning that idea into a ranking system for blog comments (we've already got the unused "comment karma" field available for storing the info). But I'm lazy. Oh, and I don't have a lot of free time. :)