Apple unveiled a software roadmap for the iPhone yesterday, including plans to make the device more enterprise-friendly as well as open the handset up to third-party applications.

The iPhone SDK is not, however, a path to total application freedom. Apple will oversee any apps designed for the handset, and the only way users will be able to download new applications will be through iTunes. Developers can set whatever price they like for their creations and Apple will take a 30% cut; free applications will be distributed at no charge. Apple’s CEO Steve Jobs said the company’s monitoring of the applications could become more “liberal” as time goes on, but for now tight control means better security and reliability.

In addition to the iPhone SDK, Jobs announced more features that make the handset enterprise-compatible, including better links to the popular corporate e-mail and organizational tool Microsoft Exchange Server.  The iPhone’s gaming potential was displayed with a demonstration from Electronic Arts of a game the company developed for the handset.

A beta version of the SDK was available yesterday, and a full version will be available in June. As a bonus venture capital firm Kleiner Perkins Caufield and Byers has created a $100 million iFund to support new companies developing next-generation applications.