User blog comment:Jimeee/Hearthfire confirmed as the latest add-on. Official trailer./@comment-5430966-20120908001740/@comment-3492791-20120908002513

You can not place any funiture. The only mannequins that can be attained come with the armory room. As I do not have the DLC myself, and that information is not avalible here on the wiki, I can not say how many that entails. However I can assure you it is a finiate amount not determined by the player.

So you can't have an entire house as a museum.