I think we don't need to choose and to modify one answer as "accepted". Beside that it's not real, we've already got the community acceptance by votes: the best answer has been voted up.
A question with upvoted answers doesn't count as "unanswered".
However, if we see an orphaned question with a good answer but without upvotes, I encourage upvoting the good answer. On the one hand, we would show which is a good answer and has community acceptance, on the other hand the question would be removed from the "unanswered" list.
See also:
- OK, Now Define “Answered” by Jeff in the blog
- What to do about old orphaned questions?What to do about old orphaned questions? on meta.SO
- Let editor/admin accept answers in abandoned questionsLet editor/admin accept answers in abandoned questions as one example of the duplicates on meta.SO
It's good to talk about this topic on our site, so thanks to Martin for bringing it up here.