People don't code on iPhone, they code on the desktop/laptops, and they use XCode which is only on the Mac. This is WWDC, Developer conference and such there should be information about the actual Mac development platform, Macintosh OS.
Umm.... there are currently dozens and dozens of Mac dev sessions announced for WWDC:
http://developer.apple.com/wwdc/sessions/#focus=iphone,it&type=lab
If it's like past years, more sessions will be announced as the week progresses.
Edit: and that's not counting the labs!