Please, Gizmodo has hardly revealed anything. They don't even say what hardware is in the damn thing. And since it was deactivated so quickly, they can only comment on how the device looks and what ports it has. There is plenty left to hype, because what Gizmodo has only allows a taste of what the final product will be like.
While that's true, Apple hasn't ever done a "leak" before with the iPhone and Jobs is known to be pretty heavy handed when it comes to revealing stuff to the public. They like keeping their cards close to their chest, they like doing their big press conferences and they're not hurting for cash so they don't need $5k from Gizmodo. Besides, if this one thing the iPhone has taught us about Apple it's that they like control... and giving info to Gizmodo ahead of their unveiling loses them control on marketing.
Gizmodo, on the other hand, is riding this as far as they can. They even went as far as to post the name of the Apple employee who lost the phone as well as a transcript of a phone conversation with him. Which they wouldn't bother to fabricated if this was a fake leak... and is also a pretty jerky thing for Gizmodo to do.
Why would Apple admit that it's a leak? It serves their purposes much better if it looks like an accident that they're now doing damage control over.