In relation to the usability, I stand by my comment.
A lot of people will get Windows 8 by default and those are the type of people who have no idea to "just install classic shell" or whatever. The UI study was examining how effective the user interface was and it has a lot of issues unfortunately. There is a lot they can do to fix it but traditionally Microsoft doesn't do that sort of thing until the next OS.
Also just a PSA for any Windows 8 gamers: fullscreen games still retain control of the display even while frozen. I have no clue why they changed this. This means a frozen game can force a reboot since you can't bring up Task Manager to force kill it for some reason. What I finally figured out was that they made Task Manager default "Always on top" to off when in every other version of Windows its on for precisely that reason. Tick it on and you can kill stuff again.