Just replacing a laptop's keyboard with a touchscreen is doing it wrong. Sure, physical layout is no longer a constraint, but touch-typing on such a surface will murder your fingers.
What I want is basically Courier. Touch to navigate, pen to create (and I don't mean some basic stylus, I mean accurate, pressure-sensitive EMR pens like Wacom and N-Trig), add a USB or Bluetooth keyboard if needed. It seems like nobody can be bothered to make such a system, though...well, maybe except the folks behind the Kno, but dual 14" screens at just under 6 pounds wouldn't do wonders for portability.
And as for alternative convertible tablet designs, what I want to see is something more along the lines of the Acer TravelMate C200, the HTC Shift, or that Intel UrbanMax concept. That is, something like a slate whose screen then slides out and pops up like the HTC Kaiser (AT&T Tilt) or Rhodium (Touch Pro2). Seems like it would be more solid than the popular single swivel hinge; I've had to retighten a few screws on my Gateway E-295C/C-14*XL's hinge twice already, though other units like the HP tm2, Toshiba M750, and Fujitsu T5010 feel much more solid in that regard.