Hi,
YuviPanda, prtksxna, and myself (with help from Tim and Aaron) have been working the UrlShortener extension, which is designed to implement the URL shortener RfC[1] (specifically Tim's implementation suggestion).
I've filed T108557[2] to deploy the extension to Wikimedia wikis. We'd like to use the "w.wiki" short domain, which the WMF is already in control of.
A test wiki has been set up mimicking what Wikimedia's configuration would be like: http://urlshortener.wmflabs.org/, and has an accompanying "short" domain at us.wmflabs.org (e.g. http://us.wmflabs.org/3). Please play with it and report any bugs you might find :)
[1] https://www.mediawiki.org/wiki/Requests_for_comment/URL_shortener [2] https://phabricator.wikimedia.org/T108557
Thanks, -- Legoktm