Chevron Human Energy TV Campaign

Now showing on a tv near you and on Chevron's website, from the manhole commercial:

Some say that by 2020 we’ll have used up half the world’s oil. Some say we already have. Making the other half last longer will take innovation, conservation…and collaboration. Will you join us?

When exactly is (or was) the peak? Does it much matter? Chevron says "it's clear, the era of cheap oil is over." What exactly happens when oil demand outstrips supply? Do we understand what we all face with shortages?