Geothermal Heat Pump Development Act of 2007 - Amends the Internal Revenue Code to: (1) to include equipment that uses the ground or ground water as a thermal energy source or sink to heal or cool a structure (i.e., geothermal heat pump systems) as energy property for purposes of the energy tax credit; (2) allow a residential energy efficient property tax credit for 30% of qualified geothermal heat pump property expenditures; and (3) allow accelerated three-year depreciation of geothermal heat pump systems.