All that changed after the iPhone special event on Thursday. Not only did Apple announce that it was giving IT managers everything they’d asked for in an enterprise cellphone — from push e-mail to a kill pill for lost or stolen iPhones (see here) — it released a software developers kit (SDK) that gives third-party programmers the same tools Apple’s inhouse programmers used to write the apps that come with the iPhone.

The message was clear: Apple is going to battle RIM for the hearts and minds of developers, the key element in any successful computing device. As Piper Jaffray’s Gene Munster put it in a report to clients this morning: “The platform with the most active developer community will likely win the battle in the mobile computing arena.”

So how are programmers reacting to the new SDK, which was made available as a free download to registered developers? One sign was that Apple’s servers nearly ground to a halt trying to handle the demand.
Valleywag
‘s Jordon Golson reported at 3:20 p.m. Thursday that he could barely get to the info page.

The developers Apple trotted out to demo — EA, Salesforce, AOL, Epocrates, Sega — certainly seemed pleased with what they were able to produce with two weeks lead time (see here). And the consensus among developers polled after the event was that the SDK exceeded expectations. (See, for example, Ephraim Schwartz‘s roundup for
InfoWorld
.)

“The tools look awesome,” wrote John Gruber on
Daring Fireball
. “Far better and more advanced than what most Mac developers were expecting.”

Gruber believes developers will accept the terms of the business deal the company is offering them — albeit somewhat grudgingly. “Apple’s 30/70 split with developers is steep, but initial reaction from the developers I follow on Twitter seems to be positive. Paul Kafasis of Rogue Amoeba told me via IM, ‘70%? That’s… that’s… livable,’ which seems to sum up the consensus sentiment.”

But “the $99 fee for getting your app listed in the store [per-developer, not per-app] is a no-brainer,” Gruber adds. “This is going to be a gold rush.” (link)

Despite the initial enthusiasm, taking on the BlackBerry in its home turf is not going to be easy. The iPhone may have captured 28% of U.S. smartphone sales last quarter versus RIM’s 41%, as Jobs proudly announced yesterday, but the installed base of BlackBerries in corporations probably approaches 10 million. The only two companies Apple could name that were using the iPhone as an enterprise device were board-of-director buddies Genentech and Disney.

The first obstacle the iPhone faces are the corporate IT departments that would have to support it. IT is heavily invested in RIM across the board, not just for all those BlackBerries, but for the RIM servers that push data to them.

Moreover, the end users Apple is targeting — all those road warriors with little bricks clipped to their belts — have also made an investment of sorts, an investment of time, energy and brainpower training their thumbs on the BlackBerry’s miniature keyboard. Their complaints about the iPhone’s touchscreen echo the contempt PC users raised on DOS had for the original Mac, with its mouse and graphical user interface.

As Piper Jaffray’s Munster points out, Apple lost the OS wars to Microsoft (MSFT) in the 1980s not because it used a mouse, but because it lacked the support of a robust developer community. In the mobile OS wars to come, Steve Jobs seems determined not to make that mistake again.