In time Mainframes of this age will make a come back.

This whole idea that you can connect lots of cheap low capacity boxes and drive down compute costs is already going away.

In time people will go back to thinking compute as a variable of time taken to finish processing. That's the paradigm in the cloud compute world- you are billed for the TIME you use the box. Eventually people will just want to use something bigger that gets things done faster, hence you don't have to rent them for long.

It's also interesting that computing capacity is no longer discussed as instructions per second, but as Giga Watts.