I just noticed that the Steam advert is the same as it was back before 2.50 was released. Mentioning in case you wanted to update it for whatever reason.
http://store.steampowered.com/app/325580/Download X Rebirth: The Teladi Outpost
A thank-you gift for all X Rebirth owners: DLC "The Teladi Outpost" for free
Together with the general availability of Update 2.50 for X Rebirth, which will be released soon, bringing a new menu system, external camera, new small shipyards and many other improvements, we are happy to announce today the DLC - X Rebirth: The Teladi Outpost - coming in December 2014: