I'll post my answer only because it happens to be the exact opposite of MGOwen's -- the biggest challenge facing SE sites is stopping them from deteriorating into normal forum sites that nobody wants to visit. For the first couple hours of the Unix/Linux beta that started yesterday it looked dangerously like we were going to have more poll questions than not -- a majority of questions that have no true answer.
I'm of the opinion (and close war logs on SO seem to agree) that the people most inclined to participate in these communities are also the people least interested in reading about what IDE you think is best to write C# code in Linux. New SE sites are particularly vulnerable because there aren't any precedents for that sort of thing, and people have a really bad habit in betas of posting any question they can think of, no matter how unneeded it is, Seeding an SE beta is useful, but asking whatever subjective question you can come up with just so you can say you asked one of the first 100 questions on the site is not the way to set up the site as the authority on that topic; it does just the opposite
I would much rather a site be forked off that is dedicated to these sorts of things, like the Not Programming Related proposal. People that like those questions can have their fun there, and leave the other sites for actual questions.
I asked on a poll question once why people insist on posting them on SO instead of a site meant for that sort of thing, and the much-upvoted reply was that SO has a far better community than those sites, apparently completely missing the obvious: There's a reason that's true