Yup, as expected Apple made the announcement that their iPhone SDK is now available.

Starting from today developers will have access to the same APIs and Tools that the developers at Apple use to create iPhone applications. Third-party developers will also have access to hardware-accelerated 3-D graphics, location-enabled applications (think Google Maps), accelerometer access, and access to the iPhone's media capabilities.

Apple said they will not restrict VOIP (voice over IP) applications that use Wifi, but will not allow VOIP applications that use cellular networks.

The SDK is based on current Mac OS X technology and is broken down into the following sets:

Cocoa Touch
Cocoa Touch contains Multi-touch events, Multi-touch controls, Acceleromter, View Hierarchy, Localization, Alerts, Web View, People Picker, Image Picker, Camera.

Media
Core Audio, OpenAL, Audio Mixing, Audio Recording, Video Playback, JPG, PNG, TIFF, PDS Quartz, Core Animation, Embedded OpenGL

Core Services
Collections, Address Book, Networking, File access, SQLite, Core Location, Net Services Threading, Preferences, URL utilities

Core OS
OS X Kernel, BSD TCP/IP, Sockets, Power Management, Keychain, Certificates, File System, Lib System, Security, Bonjour

A software iPhone emulator for Mac OS X is provided to help with development.

Apple also confirmed that native iPhone applications will only be available through the iTunes App Store via a wireless download interface. Developers will receive 70% of their chosen price which will be paid monthly, with no other recurring fees.