Err. You're either being ironic or you don't know what you're talking about.
It's free. It's available now. Download it if you can code.
Did you download it?
It seems one needs a key to upload compiled applications to an iPhone.
The key costs 99 dollars a year, or so the Apple site says.
I cannot try it out until the weekend so. If it turns out that the SDK is usable (beyond running applications in the emulator), I will have been wrong.
"Well, if Apple didn't make it clear in their video, or on their website, you must pay the $99 (standard) or $299 (enterprise) in order to transfer an application to an iPhone for testing."
http://www.tuaw.com/2008/03/07/dude-wheres-my-iphone-sdk-remote-debug-mode/