Is it possible to change the chosen answer?
Is it possible to give users with sufficiently high scores the possibility to "un-accept" answers that were accepted by question owners?
Here is a real-life scenario. A user asks a question about. Another user supplies an answer that is correct at the time of writing. The question owner accepts the answer, but then the reality changes and the answer isn't correct anymore. Another user leaves a comment to the originally accepted answer and also supplies an up-to-date answer, which gains many upvotes. However, question owner does not bother "un-accepting" the outdated answer and "accepting" the correct one.
In that specific case the original question dealt with a missing feature of PyDev (python IDE), the originally accepted answer was "there is no such a feature", but then this feature was added to the program and relevant answer was added.