See this 'question': Reasons Why Your Should NEVER Hack WordPress Core.
I think non-questions are alright, as long as they're structured as questions. You know, jeopardy-style. The aforementioned example could have been stated "Why might you not want to edit the WordPress core?" That way people can provide their own answers, and the OP could also provide his own answers too.
Non-questions like the one you referenced should be community wikis (and I see that one was marked as such). Some other examples of non-question wikis:
I'm not that familiar with the community wiki feature, I'm pretty sure it's a great thing, but I doubt it has been made to be an answer to the question.– hakreSep 15, 2010 at 1:19
Usually, questions that have no clear single answer are marked as community wiki. So in cases where you might be asking for a list of theme resources (wordpress.stackexchange.com/questions/29/…) you aren't looking for a single, definite answer but a list of good ideas ... this serves as a community resource and is "owned" by the community as a wiki. You don't gain reputation for answering/commenting on/voting on a wiki, either ...– EAMannSep 15, 2010 at 4:52
@tnorthcutt As I interpreted it that is what Jeff Atwood suggested to do in last weeks moderator chat although he said it should be done on meta. So in general yes, but maybe on meta instead of on the main site.