I think Tampa Bay will have decent (improved anyway) attendance when they move into their new stadium, but the Marlins badly need out of Florida. A new stadium will help a little, but once the novelty and new stadium smell wear off, I'm afraid it'll be back to this.
I think relocation is the answer rather than contraction - the Nats have proven that even a perennial cellar dweller can draw (decent enough) support when relocated to the right city.
The last player poll I saw regarding what cities should be next to get a baseball franchise had Las Vegas as the overwhelming favorite (with I think Nashville 2nd or 3rd and Chattanooga somewhere in the top ten).
Where does Volnation think they should end up?