Mobile will look similar to Charlotte just after BOA was complete. RSA will still be the tallest, but some decent sized 3-4 hundred foot condo towers are likely, and will add density fast. Mobile really does not have to complete to many buildings to have a dense skyline because it has such small street blocks that buildings are inherently close together, thus giving the illusion of higher density than a large block grid similar to say Atl if both had the same number and size of buildings.
Houston will add 150 new buildings downtown in the next 25 years, mostly in the 3-5 hundred foot condo range. And overall will have the most affordable new construction skyrise units in the developed world.
That will really make it not really comparable to anyone, except maybe Chi town.
Atlanta will add 150 new buildings in the "intown 3". Most will be luxury office and luxury condos.
That will make the Midtown/Dtown combo similar to Chi-town pre-current boom.
Miami is flat out unpredictable because it has soo many variables. It could boom out of control to where it is comparable to any city in the world, or it could fall flat on its ass after this current build out.
Of course I like everyone else has really no damn clue what will happen, but I could provide reasons why I believe what I wrote some basic estimations as to what the future might look like (most of which is speculation based on policy/demographic/trend analysis)