All of you folks wishing for the band to play New Yankee Stadium or Citi Field probably have not thought it all the way through. Both venues would be far worse than Giants Stadium for a stadium show. The width of a baseball stadium (because of the shape of a baseball field) would make any contemporary ballpark a poor venue for a 150 foot-wide concert stage. Baseball parks also do not allow concert promoters to sell tickets in the infield, which creates a large gap between the crowd on the field and the crowd in the grandstand. In addition, the upper deck sightlines at both new NY ballparks are poor (compared to Giants Stadium) due to priority placement of corporate suites.
The only exception to this baseball stadium rule may be 95 year-old Wrigley Field, which has very little foul territory and an outdated (but beautiful) low slung 2-deck design. As I mentioned in another thread, we know Wrigley won't be the Chicago venue because the Cubs have deals in place with Elton John, Billy Joel, and Rascal Flats, which fills their 2009 allotment with the city.