Apple said today that the iPhone, which faced serious hurdles vaulting into the enterprise, is going to support Exchange 2003 and 2007, Microsoft’s corporate e-mail, contact and calendaring product, a move expected to give the eight-month-old iPhone better purchase in its wrestling match with Nokia and the Blackberry.

It could even help push more Apple computers into the enterprise.

Apple’s worldwide marketing capo Phil Schiller said the iPhone will now work directly with Exchange Server using Microsoft’s ActiveSync protocol, which Apple licensed. So the contacts and all on Exchange will appear – poof! – on the iPhone. Push e-mail. Push calendaring. iPhone will also be compatible with the ActiveX directory. And IT will be able to wipe the iPhone remotely. A big deal to corporates.

Nike has tested it. Ditto Disney, where Apple CEO Steve Jobs is on the board.

The widgetry will be available in the next iPhone software release that Apple said would be out in June.

Besides stuff like global address lists that Exchange provides, iPhone 2.0 will also support Cisco IPsec PVN, which means the enterprise gets encryption, multi-factor authentication, certificates and passwords, identities and enforced security policies.

iPhone 2.0 will provide a configuration utility that sets up a lot of iPhones at once including password policies, VPN settings, e-mail server settings, the lot.

The announcement came as part of the event unveiling the SDK that’s supposed to let third-party developers write native programs for the Mac OS X-based iPhone and sell them through what Apple calls the App Store on a 70%-30% revenue-sharing basis.

App Store is a new application that will let users browse, search, buy and download third-party apps. Enterprise customers will be able to create private pages accessible only to their employees.

Apple says it’ll cover all the credit card, web hosting, infrastructure and DRM costs associated with App Store but it also gets to approve the applications and a sales exclusive.

Software written for the iPhone also works on iPod touch or will with a software update.

The SDK, described as using Apple’s internal APIs and tools, is available now for free. But it, like, the iPhone 2.0 software it come with, is still a beta, Apple said, and so Apple is limiting the number of developers it lets into its new iPhone Developer Program and lets test their code on the iPhone. There’s a Standard Program for $99 a year and an Enterprise Program for $299.

It will start in the US and expand out from there. Apple is accepting applications now from enterprise customers who want to join its private iPhone Enterprise Beta Program (www.apple.com/ophone/enterprise.)

Jobs said iPhone owned 28% of the American smartphone market in the fourth quarter to RIM’s 41%. The iPhone, he said, represents 71% of US mobile Internet use.

There are, it seems, already a thousand app available for the iPhone.

See www.developer.apple.com/iphone/program for the SDK.