If you take a look at our states on Area51, the two big areas that are still a problem for the beta are the rate of unanswered questions (which is close to 25%), and the average number of answers per question (which is about 1). These are related statistics.
Looking through our queue of unanswered questions, there are some that might be answerable, but that I cannot answer, and many that look unanswerable or very low quality. Many of the questions are very old.
Should we make a more concerted effort to close questions that are old and unanswerable? What criteria should we use to decide if a question meets that standard?