I'm sure other computer makers knew battery life would improve with the new chips, but I bet they didn't plan that Apple was going to make all-day-battery-life "the new thing" in laptops. The new MacBook Air's battery lasts something like twice as long as last year's.
My older laptop's 2 hour battery life is pretty sad by comparison.
The same applies to the iPhone and other cell phones. Every 2 years or so they can double the speed for the same amount of power use. Which is what they've all done so far. But someday they can choose to keep the same speed and drop the power use in half. (Or somewhere in the middle: a small amount faster and lots less power.)
As all the other cell phone makers are caught in the same "fastest processor" race that the old computer companies were, they'll get left behind by Apple.