User blog comment:Jimeee/Hearthfire confirmed as the latest add-on. Official trailer./@comment-108.80.190.175-20120830183621/@comment-294719-20120830210926

Probably. Of course, it would take a sh*t ton of resources and time to make, not to mention the fact that it would slow down your game massively due to the fact that everything in it would be located in the actual game world rather than its own little "sub-world" (as most interiors in the game currently are).