iPhone SDK NDA Remains in Place for Patent Reasons?

One DaringFireball.net reader speculates that the reason that Apple is maintaining the Non Disclosure Agreement (NDA) for the iPhone SDK is due to patent reasons.

We know Apples been building up a patent strategy around multi-touch; maybe their lawyers believe there are patentable inventions described in the iPhone SDK and they are telling Apple to keep everything under NDA until they know provisional patents can be filed within a reasonable amount of time

By keeping it under NDA, the information is supposedly still considered non-published.