From what I heard, there wasn't much developer related talk there. Just hearing it from third parties, but they claim it was mostly just used as another place to talk about the iPhone.
There were a lot of application developer related talks, there were roughly 4-5 web development sessions which I'm sure discussed the iPhone, though the one I went to didn't. It is generally the sort of pace where you learn more when hanging around between sessions and talking to people -in my opinion.
Still, was worth paying the flights and accomadation for me :)
If you had fun, it doesn't matter what they discussed! Can't say I'm much of a Mac fan(only Apple product I own is an iPod), so I doubt it would interest me much, but hanging out with a bunch of people who you know you have something in common with is a great idea.
(looking forward to learn c++, tho)
Well, what other languages do you mess around with? :]