User blog comment:BertH/Fluid layout is arriving on December 4/@comment-3424593-20131118201328/@comment-5275700-20131118201600

Yes, the change will be to all communities. If you have any concerns, please let us know more via Special:Contact or the help forum and we can offer advice and suggestions for preparing. Also check the links in the blog post for tips and ideas from staff and other users.