Waste-to-Energy Tax Credit Act - Amends the Internal Revenue Code to: (1) extend until January 1, 2009, the eligibility of trash combustion facilities for the tax credit for the production of electricity from municipal solid waste; (2) modify the adjustment to the tax credit rate for trash combustion facilities; and (3) allow an extension of the termination date applicable to the tax credit for trash combustion facilities for facilities placed in service before July 1, 2009, pursuant to a binding written contract in effect before January 1, 2009.