Somehow Miami keeps getting them with Hard Rock Stadium...
We are going to see fewer Super Bowls for several reasons: First, the competition is greater because pretty much every NFL team outside of Buffalo and Cleveland is fighting for one. Second, the NFL pretty much automatically gives a Super Bowl to any city that builds a new stadium. (Minneapolis???) Finally, with L.A. back in the picture and Vegas coming into the picture, there are more cities in the "rotation," and they have (or will have) shiny billion dollar stadiums.
In the end, though, we'll probably see the Super Bowl in NOLA once every decade (as opposed to once every five years). It's the NFL's loss, really.