In a guest appearance on The Sports Buffet with Tim Dix and Rich Tate, President of the Atlanta Sports Council Gary Stokan said that the choice of cities for WrestleMania 27 was down to two cities: Miami and Atlanta. He also said that the announcement would be made on February 1, the day after the Royal Rumble.
A Miami WrestleMania would take place at Land Shark Stadium, formerly Joe Robbie Stadium, home of the Miami Dolphins and the Florida Marlins. It seats around 76,500. In Atlanta the Georgia Dome would be used, which holds 71,000 and was the site of Goldberg's title win over Hulk Hogan in 1998.
Note that the 2010 Survivor Series is scheduled for Miami.