Just to cement that Apple is now structuring the entire company around the iPhone, the latest iPhone SDK is available now and will only work with OS X 10.5.3, which dropped today.
iPhone SDK build 9M2192, beta 6, clocks in at a whopping 1.2GB and brings with it the usual bug fixes. Of course, it's sure to have developers delving through its code looking for any clues to the App Store and the next iPhone.
Happy hunting developers.
Links:
[1] http://developer.apple.com/iphone/
[2] http://www.maclife.com/article/10_5_3_is_ready_to_rumble
[3] http://www.maclife.com/article/3g_chipset_info_found_in_sdk
[4] http://www.maclife.com/article/apple_posts_sdk_event_video
[5] http://www.maclife.com/article/iphone_sdk_elite