Phoenix would be a good choice as well, despite the heat. Miami would be a big no-no in my opinion. San Diego is the best pick though imo.
I know Miami has historically been a bad MLS site and even professional site but you can't help but think that a city as big as Miami with a large latin population can be somewhat successful. I also think Orlando would be a decent site.
Phoenix is definitely a good market, I know they hosted alot of the MLS preseason games and the attendance was great. They'll just need to probably build a retractable roof, dome or something along that line to battle the heat.
Other places of interest would be Detroit(not in this economy though ), Orlando(like previously mentioned), NY 2(Around Queens), Hartford Connecticut, San Antonio and maybe Charlotte?
Okay, it is almost the end of the regular season now and 9 teams are already in: Sporting KC, DC United, Chicago Fire, NY Red Bulls, Houston Dynamo, San Jose Earthquakes, Real Salt Lakes, Seattle Sounders, and LA Galaxy.
FC Dallas, who has a poor performance during the first half of the season, is keeping on rising and is now only 3 points behind Vancouver Whitecaps with only two matches to go, and the Caps already lost today. If both teams end up at the same points the Hoops will get the last spot via tiebreaker.
BTW, if FCD somehow gets in, Julian De Guzman will have the last laugh at Paul Mariner and TFC management no doubt.