It is unfortunate when wikis must close, but if they do close, it is up to us to inform others it has. We haven't been doing so for the past year, and so we're changing that. Starting today, closed wikis' URLs will redirect to a shutdown message. This currently only applies to .mywikis.com addresses. .mywikis.org addresses will be converted either later today or at a later date. Previously, wikis' URLs would not resolve at all.