[Good idea indeed][1], as long as we limit that for only a few topics which are **really** recurring. 

We don't want to turn any frequent topic into such thing, though. The purpose of Super User is to provide feedback to individual questions, not to be a farm of "how to" questions. There are sites dedicated to such goal, like the [how-to geek][2].

Such questions should be references of common steps to follow, but not the ultimate answer to all these questions. The purpose of such "faq" would be to post as a comment, as an initial read for the poster, and suggest him to update his question with any specific and additional details.


  [1]: http://superuser.com/questions/tagged/faq
  [2]: http://www.howtogeek.com/