Urban planning student here. Height is actually something we should not want right now. Allow me to explain.

First of all, geography puts Detroit at a disadvantage. New York City has bedrock just below the surface and Chicago has thick glacial clay, while Detroit's earth is soft and wet. That doesn't make skyscrapers impossible in Detroit, but it does make them cost significantly more to develop. That's one of the primary reasons why Walter P. Chrysler took his money to NYC to construct the Chrysler Building instead of reinvesting it in Detroit. So, I hate to tell you this, but those who responded to you previously were correct. Even with favorable topography, construction costs increase exponentially with each new floor of a building, and going above 6-8 floors would likely require rental rates of at least $2.25 per square foot. Yes, there are units Downtown currently renting higher than that, but a new luxury residential high rise would oversupply the market, pushing rates back down.

But that's okay. Take a look at this map of Downtown Detroit, which shows all of the parking in the Central Business District. Not counting garages with first floor retail like the new Z-Lot, parking lots and decks are unproductive urban dead zones. There have actually been studies that show people stop walking down a street when the streetwall (buildings reaching right up to the sidewalk) ends. And then there's the fact that they produce very little tax revenue for the city. So, the excess parking Downtown has created an environment that discourages foot traffic, resulting in a feedback loop of fewer people and a lower quality urban experience. Compare Detroit to Downtown Chicago, which has been building 3,000-4,000 residential units annually for the last two decades. That's enough for nearly a dozen high rises each year. Detroit is smaller, and our residential demand is almost certainly always going to be smaller than Chicago's. So, let's say Downtown Detroit can absorb a highly optimistic 500 new residential units this year without causing prices to plummet. Which would you choose: one high rise that enhances a few blocks of the city or 7-8 new buildings spread throughout Downtown?

Now, I know what you're thinking. Skyscrapers are awesome. I can't disagree with you there, but I can offer a new perspective. Think of the coolest cities in the world. Perhaps Paris, Venice, London, Budapest, Barcelona, or Washington D.C. came to mind? My point is that skyscrapers are not a prerequisite for a great city. They are simply a response to a lack of space in the city center.

So when will we see new high rises? Well, we might get a few token skyscrapers to stroke the ego of a couple people with too much money, but a skyscraper boom will not happen until the vast majority of the parking and vacant lots have been developed in and around the CBD.

If I had to guess where we might see new high rises in the near term, I'd say east of the RenCen, the Greektown area, and in the new Arena District because that's where the egos are. However, if I were a property developer with an unlimited budget, I'd build on the parking lot by Campus Martius because it's one of the greatest public spaces in the country.

Hope this helps. I'm glad I had something to contribute for once.

tl;dr No skyscraper boom anytime soon, but that's a good thing because it means development will be spread throughout Downtown and we'll soon have a nice, walkable city center.