In short, as long as computer has more power, programs would require more power.
Of course, there can't always be more power. That curve will end. At that time, computers would have to look at other ways of getting along.
First, there is specialty hardware. That hardware would do special tasks better than the main hardware. Example: Video Cards
Next, there are other efficiencies which I don't remember.
The last efficiency to occur would be the OS getting efficient. Microsoft nicely showed that with Vista, which anticipated more power, but that more power never came. Now, with Windows 8, they wrote it with no anticipation for more power.
Although computational power has increased, the power of computers has no increased, or has even decreased (such as smart phones and tablets). We are at the point where raw power has no payoff for a large segment of the population.
