PHILADELPHIA--(BUSINESS WIRE)--Comcast Corporation (Nasdaq: CMCSA, CMCSK) today announced the launch of Xfinity in UHD, a 4K Ultra High-Definition (UHD) On Demand programming app for 2014 Samsung UHD TVs. Debuting with full current seasons of TV shows from NBC and USA Network, the Xfinity in UHD app library will continue to expand with On Demand programming across multiple networks and studios and is completely free to Xfinity TV customers whose video subscription includes participating network