This is from the July/August issue of Discover magazine:
Hawking is now pushing a different strategy, which he calls top-down cosmology. It is not the case, he says, that the past uniquely determines the present. Because the universe has many possible histories and just as many possible beginnings, the present state of the universe selects the past. "This means that the histories of the Universe depend on what is being measured," Hawking wrote in a recent paper, "contrary to the usual idea that the Universe has an objective, observer-independent history."…Hawking's idea provides a natural context for string theory. All those universes might simply represent different possible histories of our universe.