As we all know, just because an article is old, doesn't mean it's useless. We should have a small feature some where, maybe on the home page, that randomly picks 5 or so articles with 4 or more stars and displays them in a small list.
Beside the article, you can put a little number like: Bézier Curves for Dummies (4.7/5)
Heh... well, I actually think that articles have one of the longer lifespans as far as TDC content goes, just for the fact that so few people write them. I only just discovered all of the awesome articles that are still on the front page from up to months ago, now.
If you're gonna do a little random selection/recommendation thingy, there should definitely be one for games, which generally have about a week before they're forgotten completely.
It's nice to keep features like the list of top articles, and the search feature, but it's also nice to have a little spot that's tucked away in the home page. Then if you get bored enough that you notice it there, you can casually click on an article, and find something very interesting to just... read, and learn from.
It'll keep good articles alive, and give people something to read if they're just, well, bored.
Edit: I'd be a good idea to consider articles with at least a 3 or above, cycled. It shows at least half the people who read it (and decided to vote), found it useful or informative.