Unfortunately, I don't see it coming. Recent Dell's experience with selling laptops with pre-installed Ubuntu on them failed permanently. Also, in 2010 BBC migrated all their workstations to Ubuntu and trained all employees on how to work in this OS. The funnies part came later when BBC surveyed their employees trying to find out how many of them switched to Ubuntu at home. Result - 2%. It's quite possible that Linux-based PC's will start overtaking the residential market but I frankly don't see it happening in foreseen future.