I am pleased with the overall design philosophy direction that Unity and Gnome 3 have taken in abandoning the 90s clutterbuck desktop in favor of something cleaner and more fluid, but both are immature. But if they can pull it together, and can be combined with the "ultrabook" movement to make non-Apple laptops not look like shit, then we might have something.
Also, look into cheap Chinese tablets like the "a-pad." If these could be flashed to run an open platform, then we'd have something there too.
But the big problem remains design. OSS is very good at innovation and infrastructure, but is very, very, VERY poor at user experience.