Found this image over at Chicagoist, showing Chicago with buildings now under construction or proposed inserted into the city's skyline. Many more images and views are in the Chicago Model Thread at SkyscraperCity.
Makes me think that this view won't ever really happen, because even if the proposed buildings are built, there'll probably be more towers under construction with their tower cranes dotting the skyline. Especially in times of progress, the city is never complete, it's always evolving.