I am sure that would also lead to another concept: CPU power/time cost:
You would be able to buy 1 hour of CPU power at 10GHz to process your 3D project rendering, and the day after buy 1 hour of CPU power at 2GHz to process your word document... but you have to be carefull your kid would wake up in the middle of the light grab you access code and will request 15 GHZ of CPU power and other 5GB-Video RAM for 3D video to play that game he saw in a magazine...

The pros:
- You can have less and high power depending on what do you need
- You only pay for the real time you are log on...

The cons:
- privacy...
- the feel of open the case and setup new hardware :-)
- DIY is fun, that concept would end...