figure 1: John Gruber
John Gruber of Daring Fireball has posted an excellent discussion on the various subtleties of the language used in Steve Jobs' iPhone SDK letter. He talks of HTML widgets vs. the stripped-down Cocoa API, the security of the current iPhone, the hidden compliment-slash-dig on Nokia and their recent "open to anything" marketing slogan, signed apps, the iTunes App store, and with his usual attention to detail and insight. Well worth the read there, like any long Gruber post.
Gruber also points to a blog post for OSX developers that intend to write applications for the iPhone, which led to a comment-discussion by several mac developers, and where they intend to aim their development efforts -- both in functionality of their applications, and price thereof. It looks like there's plenty of hope for the $5 app, if they can be guaranteed to be paid. There's still the lingering question of how available the SDK will be -- and that's excellently addressed by Frasier Spiers on a blog post at his site.