In terms of the diagram above, the alignment of the gates seems relatively intuitive. It would be nice to have the optional for manual mode while driving an automatic car, as you see in many of the manumatic crossovers, Audis, Mazdas, etc., with paddle or stick (clutchless) shifting. It's incredibly valuable to engage manual mode in an otherwise automatic vehicle for steep mountain grades, as I saw last weekend navigating Eisenhower tunnel in my girlfriend's car.
I think the user could ultimately get used to having both options, but I think most people who drive stick-shift cars comfortably will always use the manual mode, and people who prefer automatic mode would almost never switch to a clutched manual mode, except for perhaps 'racing' on city streets.
The real (unfortunate) downfall, I think, is the mechanical complexity of the transfer case / transmission itself. An automatic transmission is incrediblity complex, including a torque converter, planetary gears, automatic clutches/bands, valve body and the whole mess of hydraulic pressure necessary to operate them. They're much heavier than manual transmissions (in hundreds of pounds). To my knowledge, it'd be almost impossible to retrofit an automatic transmission to provide the 'manual' clutched experience, so you'd essentially have to have the entire manual transmission and the entire automatic transmission, in parallel. Lots of extra weight added to the car, which translates to handling, center of gravity, acceleration, and braking, among other things. If this were a middle-of-the-road "around town" type vehicle, that might not be a primary concrn, but it would also affect gas mileage.
---------- Post added at 04:37 PM ---------- Previous post was at 04:28 PM ----------
Edit:
Is having the 'manual' gate arrangement really what's important to you about this design?
Out of curiousity, have you ever driven a clutchless automatic transmission? They really do give the benefits of both with similar weight considerations by removing much and adding a great deal of electronics. Especially in ones that allow you to toggle between modes essentially seamlessly, it accomplishes your goal without an entire new gear box and gate arrangement as you have above. There are a number of high price vehicles with incredible clutchless manuals, namely many of the Porsches and Ferrari's out there now. Likewise, some crossovers exist like the 370Z, which despite being entirely manual has rev-matching electronics, so down-shifts are always preformed precisely for engine speed and torque. My girlfriend's Mazda 6 has this:
Where the normal automatic transmission is handled with the standard column, but while in drive you can push it right into "manual' mode, which lets you force up and down gear shifts. When you come to a stop it automatically puts it into first to avoid sluggish starts, and it will automatically down-shift if you really bog it in too high of a gear. It handles the peculiarities, but it's incredibly useful to say, stick it in third gear for a steep 7% grade downhill on ice, something that would cause an entirely automatic car to navigate dangerously, forcing them to use their brakes to excess to keep the car from accelerating out of control.