Clearwire, Sprint and today finally committed themselves to launching their WiMAX-based 4G services in three of their most important markets. The companies will launch their flagship New York City access, along with rebranded Time Warner Cable service, on November 1. All will have a fallback to 3G for devices like the HTC Evo 4G or Overdrive routers that have both 3G and 4G onboard.