From AA's December 13 press release (emphasis added):
In addition, American will enhance its lounge admittance policy in conjunction with the opening of the new Flagship Lounge® and second Admirals Club® lounge at the new JFK terminal by summer 2007. First Class passengers flying on transcontinental routes on three-class aircraft will have access to American’s Flagship Lounges, usually reserved for international premium class customers. In addition, Business Class passengers traveling on transcontinental routes on three-class aircraft will have access to American’s Admirals Club lounges.