Hi Rich,
"And Ill not be saying good-bye to the 360 for a while, it will sit under the X1 as i have a couple of spare HDMI inputs on the telly."
The Xbox One has Hdmi pass-through. The idea is you can put a freeveiw or other set-top-box through it and have it overlaid with Xbox UI.
What some have speculated is that you could plug in the 360 to "pass through" and be able to play with a Xbox One controller through the Xbox One.
I'm just saying, you might still have some HDMI ports free!