Apple has released an update for the iPhone SDK, bringing the current version of the SDK to 3.1.3.
The new SDK 3.1.3 includes Xcode, which is available in versions that are compatible with Leopard and Snow Leopard for iPhone and iPod Touch developers.
The SDK update, according to information we received from a developer, is required if you plan on developing apps for devices running iPhone OS 3.1.3. According to Apple, the corresponding iPhone OS 3.1.3 update contains importantand .
If you are interested in developing for the iPad, you will need to download for specifically for the new device.
If you've seen and used this new update, please tell us about your experiences in the comments.