Is there a business base there to justify all that investment?
There is a growing Tech sector in Michigan. Its also right next to the heart of the Canadian manufacturing region. Also, Detroit is the second busiest freight crossing on the north American continent. Quicken HQ is there, JP Morgan has a regional HQ there, Ernst & Young has a regional HQ there. Compuware HQ is there.
Take a look at downtown Detroit with Google Street view sometime. The city is looking good. Forbes recently named the Detroit riverfront the best in the USA.
As far as residential is concerned, some neighborhoods are very bad still but others aren’t bad at all. Mexicantown is looking better all the time, Corktown is looking pretty good as well.