Runa Bhattacharjee has notified the community of the following:
On January 21 2014 the MediaWiki extension Universal Language Selector (ULS) was disabled on this wiki. A new preference was added for logged-in users to turn on ULS. This was done to prevent slow loading of pages due to ULS webfonts, a behaviour that had been observed by the Wikimedia Technical Operations team on some wikis.
We are now ready to enable ULS again. The temporary preference to enable ULS will be removed. A new checkbox has been added to the Language Panel to enable/disable font delivery. This will be unchecked by default for this wiki, but can be selected at any time by the users to enable webfonts. This is an interim solution while we improve the feature of webfonts delivery.
You can read the announcement and the development plan for more information.