Good news for anyone thinking about jumping to 4K in the next year or two. The new spec allows for full 60 FPS at 4k which is good for 3D and sat/cable/games.
http://arstechnica.com/gadgets/2013/09/hdmi-2-0-is-ready-for-your-next-ultra-hd-tv/
http://arstechnica.com/gadgets/2013/09/hdmi-2-0-is-ready-for-your-next-ultra-hd-tv/