#Translatewiki.net a request was made to support OpenID. The beauty of OpenID is that it reduces the number of websites that store your password. This makes browsing the Internet arguably safer.
The translatewiki staff is hesitant to support yet another nice to have extension. It has been burned by accepting LiquidThreads in the past. LiquidThreads is a great idea and it provides a much better user experience but it has not been properly supported. There is a promise for a release somewhere in an unspecified future.
Wikinaut did take over the OpenID extension support. He provided patches updated the documentation and equally important, he runs it on his own MediaWiki wikis. The need for support seems to be fulfilled, the question is not only if translatewiki is interested but also if the WMF is interested in providing improved security.