The SDK allows developers to write applications that run directly on the iPhone and consists of a new version of XCode (3.1) and an iPhone Simulator that runs on an Intel-based Mac (the iPhone SDK will not work on a PowerPC-based system). Application distribution will be through the iPhone App Store in the next version of the iPhone software/firmware.
The SDK and development environment are available as a free download from Apple’s developer site. For $99, developers will receive a signed key from Apple that lets them sell (or give away at no charge) an application through Apple’s distribution and hosting network. For applications that are sold, Apple will take 30% of the purchase price; free apps will be distributed at no charge other than the cost of the signed key.
The new iPhone Enterprise features consist of Microsoft Exchange ActiveSync support, secure enterprise-grade virtual private networking, and security features like the ability to remotely wipe/erase a lost iPhone.
Version 2.0 of the iPhone software/firmware is expected to be available to end users in June; certain developers and some companies in the Enterprise Beta program will have access to beta and pre-release versions.