Take this question for example:

https://wordpress.stackexchange.com/questions/32285/custom-permalinks-for-blog-posts-only

The first comment basically is the right answer. The question author goes on to comment to say if he does that it breaks a plugin he is using. The question author then goes on to say that he has switched to a different plugin and the question is now resolved. But because all this took place in the question comments there is no real answer given.

What do we do with such questions? Do we close it? Do we ask the question author to post his own answer? Do I or someone else create an answer based on the comments?

Personally I would vote for these questions to be closed. What are your thoughts?