But don't hold your breath.
From the 'terms and rules':
When you register for a user account you accept that any information you post publicly will remain in our database and a matter of public record even if you later decide to leave or close your user account. On leaving you may request that we depersonalise your account and remove any private information from both your account and our site, but we will not delete/remove your account or the content you have posted on our site.