With structures like Trump Tower and Waterview rising and hopefully at some point Chicago Spire, have we reached a point in Chicago's high rise development that any skyscraper to rise past 900 feet will not be commerical and business in nature, but residential like the above?

IMO, for the most part yes. I think occasionally (whenever a LARGE corporation) we will see a 900+ ft office tower, but I don't know of any LARGE companies looking to relocate their HQ to Chicago right now. But look at 300 North LaSalle, that ones almost 800 ft... Isn't Hines doing another rumored tall one thats an office as well?