Grantsville-Tooele-Stansbury Park triangle will nearly double in population.
Eagle Mountain has been quietly building for years.
Both Springville and Spanish Fork have exploded from nothing over the last 20 years.
The thing is, though, the desire to be in the main two valleys (Salt Lake and Provo areas) will always remain high. Even after the two metro areas become fully connected in the next 10 years (yep, Point of the Mountain will be fully developed in 10 years), people are going to keep finding ways to cram into where they want to be. Look no further to the concrete jungles of California cities for that model.
But the costs will drive a lot of people out, which is why those other areas have, are, and will continue to explode. Ogden, Cache Valley, Heber City, Brigham City, etc. All those areas will continue to take the main valley overflow for quite some time.