Wrong solution to the right problem
So Valve are trying to replace a mouse and keyboard with trackpads so that you can play RTSs and Diablo and other PC games in the living room?
And they've taken inspiration from Smartphones, just like the Wii U did.
But... a mouse and keyboard aren't just superior for 'clicking' games because they are more precise than trackpads. The position of the users body sitting at a desk with the screen 30cm away and his elbows and forearms rested on the table is a big part of the useability. This is the reason why people don't just use a wireless keyboard and mouse in their living room.
The problem is that we currrently have one computer (a laptop/desktop) on a desk in our study/bedroom/kitchen table for work and PC style clicking games, and another (a console) sat under our TV for games not involving precise clicking that benefit from the larger screen.
I thought Valve got this, and were going to come up with some solution to use the steam box to power both screens from the one processor. Maybe some special lag free wifi (if such a thing is possible?) or some extended HDMI cable that is easy (without a professional install) to plumb through from your bedroom/study wall to the living room wall behind your TV(again if this is actually possible?).
That way when you want to play Diablo/Rome Total War/World of Warcaft you just use the screen, mouse, and keyboard sat on the desk in your bedroom hooked up lag free to the steam box under your TV, and when you want to play a console style game on your bigger TV screen you do that on the couch in your living room with a Xbox One controller.