I think Superman Homepage is letting Busiek and DC off the hook a little too easily, Busiek and DC aren't stupid, they know what fans want to know and it sounds like they are just trying to skirt the issue. I don't like this idea of "You'll find it all out later", it sounds like their trying to avoid something.
They -are- trying to avoid something -- having to totally reinvent the past all at once just to be able to tell new stories.
I think DC is handling this the right way.
Every attempt to tell Superman's origin as a stand-alone story - from the
World of Krypton and
Krypton Chronicles mini-serieses, up through
Man of Steel and even the pure genius of
Birthright - has gone over like a lead balloon. Sure,
MOS was popular at the time, but we're still trying to recover from the fallout.
Yet the 1930s, 40s, 50s, 60s and 70s methods of just revealing it as backstory worked just fine.
Even in Superman's first appearance, his origin was just a one-page flashback.
If DC told Superman's new origin as some sort of mega-event, no matter how good or bad the resulting mini-series, one-shot, or graphic novel; no matter how old or new the continuity; I guarantee that hordes of people would object it, forcing DC to back-pedal yet again.
You've got to get people used to his new continuity, maybe even getting them to want to know more about it, before you tell what it is.