I remain unconvinced.

There has never been anything that we want "integrated" into our natural experience. This is why head-up displays remain for military aircraft but an iPad is wildly successful as a magic-put-picture-in-my-hand box. Books have, by and large, been within a factor of each other - and most of the things we manipulate easily end up about that same size. A desk from Roman times is the same size as a desk at Office Depot because our "workspace" is determined by our span more than anything else.

Google Docs allows all sorts of realtime collaboration, and nobody really uses it. It isn't necessary. It's distracting, in fact.

I probably link to this every other month or so. It's four years old and it's still en pointe. The fact of the matter is, nobody involved in these whizzbang UIs has much experience with biomechanics or human factors engineering... and the reason a Macbook Air looks a a lot like a streamlined Underwood isn't a lack of imagination, it's a lack of utility.

A distinct lack of utility is a commonality amongst all of these whizzbang ideas.