Windows 10 will run across an incredibly broad set of devices from the Internet of Things, to servers in enterprise datacenters worldwide. Some of these devices have 4 inch screens some have 80 inch screens and some dont have screens at all. Some of these devices you hold in your hand, others are ten feet away. Some of these devices you primarily use touch/pen, others mouse/keyboard, others controller/gesture and some devices can switch between input types.
I miss the avatars on the XB1 that were on the 360. It feels like they took a step backwards, but I'm glad to see some prospect of them coming back. It's a big part of the 360 feel, which was fantastic.
More like all apps are funnelled through a central store... if an app on windows 10 is available and works for both pc and xbox (as a single unified app as selected by the developer) then you'd be able to buy for both. But they will still likely segregate available apps according to which store you're currently on.
Avatars made them stupid amounts of money for very little work, I was surprised they were sidelined to begin with. Maybe Kinect Sports Rivals was a hint of the idea of new-styled Avatars, but didn't pan out, and now the idea's abandoned with Rare further gutted.
The current one have a giant wide tile showing the game running, and a few little square tiles. This one seems to show actually live tiles, with wide and big square sizes, like the ones you'd find on the windows 8.1 start screen.