For laptops it's a different story. The big push seems to be in reduction of power consumption for longer battery life, which sounds pretty sensible to me. I guess if battery life is a big concern for a PC user, then it makes sense to go to a smaller process. That does seem like a pretty small reason to upgrade, though.
Another good indicator that the PC "game" has changed is that the two major commercial PC OS's just released their latest versions (Mavericks & 8.1) for free.