There's an approval guidelines document for the Mac App Store up on the Apple developer site now. It's behind a login wall, so I assume it's under the usual NDA, but if you're a registered Apple dev, you should be able to get it at the following URL:
Isn't about time this NDA got tested in court? It seems so ridiculous that anyone can get in and read it, but no one can talk about it due to the NDA.
Non-Disclosure Agreements are well-tested legal territory, and not uncommon for proprietary SDKs (you should see some of the terms you have to agree to for some company's hardware dev kits).
What about this particular NDA strikes you as being exceptional or impermissible?
Does Apple have a reason for the NDA other than letting their developers know who's the boss?
Apple's developer site member center is down. They'll probably be posting information later today.