On a question that has a lot of answers, it's possible that a very good but late-coming answer gets buried near the bottom: few people may scroll down that far, and so the answer never attains the critical mass it needs to get the votes it warrants.
To help alleviate such problems, it could be useful to occasionally (maybe once in every 20-40 page loads) shuffle the order of the answers of some questions. This would be announced by some prominently visible cue, for example by a colourscheme modification, or a banner near the top giving the user the option to turn off shuffling temporarily (e.g. for an hour/day/week), or to cease participation in the shuffle system.
I'm not entirely certain that this is really a problem, but it does seem likely in at least a few cases that I've seen. Probably it would be a good idea to do some data analysis to find out how much of an issue this is, and to identify heuristics — e.g. the number of answers, the total length of those answers, the relative age of low-voted answers compared to that of the question, etc. — that would trigger this behaviour.
One more advanced technique for data gathering would be to set up a null AJAX GET to be run in response to mouseover events, once per pageload, for each answer . Although not useful for individual pages, it seems likely that over a large quantity of data it would produce some meaningful information, to help determine the likelihood of a new-ish answer being "stranded" at the bottom of a long list. I'm not sure how practical/ethical this sort of technique is; some users might consider it invasive.