Commuter rail for Arizona?

Last month, a study was released by the Maricopa Association of Governments (MAG, like the wheels) on bringing commuter rail to the Valley of the Sun, with possible high speed (up to 110 mph) rail service to Tucson. Among the opportunities of commuter rail are cleaner air from fewer auto emissions (and less greenhouse gas emissions) and quicker commute times than freeways. Commuter rail is different than light rail as it would bring people from far flung suburbs into the city with few stops at higher speeds along existing rail corridors. There will still be critics of the money it will cost, but as our city grows and land prices go up, building freeways won't be any cheaper.