I first thought, encouraged by this description at the Architizer, that it has been left to rot in some neighborhood gone bad, but in fact the owners just ran out of money, it sat empty for a while while being foreclosed, and was then bought by its current owners, who have poured in quite a lot of money - Wright was not actually very good at designing houses for those of modest means - to restore it to glory. I also found some photos from when it was on sale in 2006, prior to the repairs, as well as the website maintained by the current owners and an article from Detroit's Hour magazine about the house.
Expensive or not, it is a very cool house.
Addendum: Apparently it is more common to abandon Frank Lloyd Wright houses than I would have thought. Reader (and old friend) Scott points to the not dissimilar history of the Martin House in Buffalo.