translatewiki.net, it changes from a talking point into an actionable item. Wikidata is now a reality for the localisers at translatewiki. There are messages that can be translated and commented upon. They are being translated and the first comment, a typo in the message text, found its way on the [[Support]] pages.
Wikidata has the potential to make a huge difference particularly to the smaller Wikipedia projects. When this functionality is localised, it will makes the Wikidata usable to all members of all Wikipedia communities.
It will be interesting to learn if the Wikidata demonstration installation makes use of the LocalisationUpdate process. Without LU working properly there will be no daily updates with the latest localisations from translatewiki.
This same question can be asked for any and all the projects that have a presence on one of the Wikimedia Labs servers. One of the original use cases for the LocalisationUpdate extension is for it to work on any and all MediaWiki installations. When it works, a MediaWiki installation never mind if it is in India, Russia or Germany will feature the latest localisations. This provides a powerful incentive to ensure that the relevant localisations are always up to date.