[mysto]

Actually it's only the city of Detroit itself that is shrinking in population. The metropolitan area (including the 'burbs) is still growing but not by much. The Detroit metro area grew from 4.24 million in 1990 to 4.45 million in 2000.
BTW, Pittsburgh's metro area lost population (2.46 mil to 2.43 mil).

[AmishDude]

But Pittsburgh is actually becoming more livable with the decline in population (but don't tell the Pirates and Penguins). It was overcrowded during the steel era. It's an elderly town now and is settling to an equilibrium.