Actually that's the easiest part to be implemented as totally open source, and I would really like to see all drivers opened. Why do you think HW drivers are so difficult to open? The chip/module vendors should have nothing against that, since the use of the drivers implies the use of the respective HW blocks, which implies higher sales for the said HW blocks.
Why not? It would be "unlike" anything on the market. I have a feeling most "geeks" would've chosen a +5in device with super-shaved bezels. A slab form-factor with an attachable hwkbd. Decent specs, decent ux, decent price.