Paul Kafasis form Rougue Amobea on the problem of the iPhone SDK NDA. Here is the most important to me:
On the Mac platform, knowledge sharing is commonplace and resources for development are plentiful. This community is one of the best aspects of writing software for the Mac. On the iPhone, however, the NDA means no such community is allowed to exist.
Before choosing a particular technology I always look at the community first. That is why I love Rails and Cocoa. It’s filled with great developers that are gratified with the community well being, rather than just themselves.
(Via Inside iPhone.)