Let's think this thru ...
There is NO WAY to surprise an audience with Superman's origin. If someone has heard of Superman, they already know that he comes from Krypton. Having him going around as Clark and then discovering somewhere later in the movie that he's from Krypton would only be a surprise to that character. The people in the theater would already know. With that in mind, is there any reason to try to play around with making it a surprise to the audience?
Another thought that I've seen circulating thru these boards is to use Krypton in limited flashbacks so the story can concentrate on Superman from the top of the film. They could do that but it would imply that there was really nothing interesting about Krypton. That it's sole purpose in the story is to provide an explanation for his abilities. I've got to repeat myself here - I think there is a dramatic story to be told on Krypton .. and I'm not talking about some white haired Jor-el having a brief meeting with the council and then packing Kal-el in a flying chandolier and firing him off toward Earth. I would feel cheated if we didn't get a new, interesting Krypton with the reboot.
And, let me just point something out for those who keep commenting that you can't do a linear story here because Donner already did it. It wasn't unique when Donner did it. In fact, The pilot episode of the 1950's tv series did the same thing and it was in the movie serials before that.