http://www.eurogamer.net/articles/digitalfoundry-spec-analysis-xbox-one

So, again through a process of extrapolation from the drip-feed of hard facts, the make-up of the One's GPU is confirmed - 12 compute units each capable of 64 ops/clock gives us the 768 total revealed by Microsoft and thus, by extension, the 1.2 teraflop graphics core. So that's another tick on the Durango leaked spec that has been transposed across to the final Xbox One architecture and the proof we need that PlayStation 4's 18 CU graphics core has 50 per cent more raw power than the GPU in the new Microsoft console.

Microsoft wants you "to have a relationship" with your TV, and to that end, Xbox One has a new connection that no other console possesses - an HDMI input (supporting 1080p, 3D, even 4K - at least the 30Hz version of it supported in HDMI 1.4a). The idea is that you can daisy-chain your existing set-top box into the new console and seamlessly switch between TV and gameplay, and even run apps in parallel with both of them. So, for example, in theory, you can play Forza 5, switch over to watch the Formula One and take a Skype call simultaneously.