Gorilla Arm alone makes tablets a total nonstarter. Even if you don't have to awkwardly cradle the thing in your arms while you use it, you still have to hold out your arm to poke at it.
Microsoft only persisted with their Tablet PC crap for so long because the thing was designed for their middle managers to fiddle with in their constant meetings.
At the point where the display is as e-ink readable as paper, the touch part is as sensitive as an iphone, the screen is also as sensitive to pen input as a wacom tablet, and the software is good enough for touch-doodling, pen-drawing, typing, sketching, all interchangably and neatening up diagrams for you, then you will have it on your desk instead of a notepad, instead of a phone message pad, you will look down and work on it like a jotter instead of cradling it like a child or mouting it vertically at head height and arms length.
Microsoft only persisted with their Tablet PC crap for so long because the thing was designed for their middle managers to fiddle with in their constant meetings.