The Marlins and the City of Miami can go back and forth arguing between the Downtown site and the Orange Bowl site. The truth is neither spot is entirely perfect. Each site has it's positives and it's negatives. The Downtown Miami site may be too small and the site has been hand selected for a new courthouse. The Orange Bowl site is not in best area of town and generally not liked by anyone outside of Miami Politicians for many reasons...
By far the best spot in Miami is Bicentennial Park. Imagine the Home Runs landing into Biscayne Bay (kind of like in San Fran). There is PLENTY of land there. If the land was used correctly, you could build the stadium, create parking and even make a nice park outside for kids to play and people to take their pets (which is something missing in Miami). There will be 20,000+ new condos on the Miami Corridor by the end of 2008, so you will have many people living and working in the area. The site is blocks away from AmericanAirlines Arena, if that site works for the Triple A, it can definitely work for "Bacardi Field at Bicenttenial Park". Which leads me to a way to raise money in the short term to help with the building costs. They can sell the naming rights to a "Miami" company like Bacardi, NOW (like they did with the AA Arena).
The only thing about Bicentennial Park that makes the site not possible is that commissioners have already designated the site the place for a new science museum. These are the same commissioners whom approved the Performing Arts center which had cost overruns of over $100 Million. It's time for the city of Miami to wake up, put it up for vote. Should the Bicentennial Park be used for the Science Museum or Marlins Stadium. The truth is that Downtown Miami is finally becoming DOWNTOWN MIAMI. Between the nightlife, the Heat, the new buildings, the restaurants in Brickell and the financial district -- People will go to games as long as the owners promise to field a competitive team (which they would have no excuse not to do if they get their stadium).
I have called and written commissioners and the mayor about this and it always seems to fall oonto deaf ears. It's something we should all rally around -- write letters, make phone calls, do something...