For those unfamiliar with Dallas, nearly every piece of land/parking lot in that 2nd picture is either U/C or has a project in the works. The developer is playing his cards right and taking advantage of the limited land in this highly dynamic area so there is no reason to doubt that this developments could happen. I bring it up because from those pics it looks like they are building high towers in the middle of lots of land. Here is a recent picture of the projects in that area (from a different angle).
One thing that would stand in the way for this type of height is the FAA height restrictions but I don't think the developer would just throw away money on designs for pleasure. Maybe he knows something we don't. It does seem that the restrictions have been loosening for some reason as seen on other recent proposals.
http://bizbeatblog.dallasnews.com/fi...rygraphic1.jpg