http://gamingeverything.com/50054/xbox-one-ui-screenshots/

Looks like windows 8....

I can't really see any difference from the current dashboard. I guess it is slightly tweaked for larger images for the main thing that you are focusing on, but it is certainly a minor evolution rather than revolution (that the dashboard itself of course saw)

Looks nice. They kept the tiles from the current dashboard, but they seem more organized.

Exactly. That's either a good thing or a bad thing.

Windows 8, meh!

Windows 8 has always been stupid to me (too complicated), but havent played the xbox 360 so dont know much about the UI..

Looks like giant widescreen version of my phone.

Blades...where are you...

The development name for that interface is "Metro" (I believe) and it is all over the place by Microsoft   So, it isn't surprising you see it.  The 360 also has something like it to.