Unfortunately,
this design isn't going to be the one, because it comes from outside of Apple (and Apple doesn't tend to publish their concept designs like this) ... but, that said ... if their tablet ends up looking like this thing, I'd buy it in a second (imagine an apple-ified version of the OLPC2 concept).
Here's the main pic:
And here it is with the lower half being used as a virtual laptop keyboard and trackpad:
I doubt I'd use it much that way, as I've said before, I hate virtual keyboards. I might in a highly mobile pinch, but I'd be more likely want to use it as a tablet, maybe with dual thumb keyboards for quick work. Then I'd just use my matthias folding USB keyboard with it when I'm at a desk/table.
The images say it's a 13" screen (A4 paper size) when fully flat open, and that each half screen is about 8.5" screen size. Unfortunately that doesn't fit with the 10" screen rumors (in either mode). But, still, if this is even close to what Apple is planning, I'd probably jump right back into "full on Apple Fan Boy" :-} (though, probably still not with an iPhone).
That thing as a 10" screen fully open, or as a 10" screen when in half-tablet mode, would be an amazing mobile device.