I'd say the real help would be in a new generation of cheap ARM servers. They're mostly impeded by how much variability there is in ARM processors, but having

I'd say the real help would be in a new generation of cheap ARM servers. They're mostly impeded by how much variability there is in ARM processors, but having your drivers in the mainline kernel would make it far easier to sell to hardware manufacturers. I'm sure there's some incentive to keep these drivers closed source, but the potential business benefits go far beyond mobile devices.