With the way processor and graphics performance have improved, in the future I tend to see the pc becoming like a home server. 1 pc in the home would provide as many virtual desktops as needed. The pc can be in a remote location, basement or mechanical room - so if needs really loud fans for cooling then it's no problem. All you have on your desk is a monitor and a little box for disk drives - no cooling required. I have a hard time thinking of 5+ ghz processors in any other context that doesn't seem like a total waste of 4 ghz
