We’re launching the new theme directory this week, and it comes with some URLs redirects.
Most importantly, wordpress.org/themes/ will be served from the WordPres.org MU going forward, so themes will be just a site on that network.
Trailingslash all request without a query, /themes => /themes/ /themes/tag-filters/ => /themes/ /themes/search.php?q=[term] => /themes/search/[term]/ /themes/[themename]/stats/ => /themes/[themename]/ /themes/[themename]/developer/ => /themes/[themename]/ /themes/about/ => /themes/getting-started/ /themes/contact/ => /themes/getting-started/
We don’t have a specific date/time for the switch yet, but it will be on 2/25 or 2/26.
Posting here to give you a heads up and some time to get it prepared.