This would basically lead to a situation that instead of two systems that support different set of hardware we'd have three. Instead of two different systems with slightly different quirks, we'd have three systems with different quirks.
New driver system would also mean that 3d drivers would need to be written from scratch.
Well, we would only end up with 3 different systems because neither of the two existing are willing to open up their SDK... As always, the lack of open-mindedness is what makes people reinvent the wheel... over and over.
