Enterprises married to the BlackBerry won't switch any time soon. But any with an eye to the future are likely to invest in trial programs with iPhones. Someone in IT is going to see to it that some experimentation is done with the new SDK for enterprise-critical apps.
Meanwhile, forward-looking firms that may still be using Treos would be first candidates to switch to iPhone.
Companies have been putting the brakes on IT spending since last August's market scare. IT cuts won't help Apple make a big splash this Summer, but early adopters in enterprise IT should start spending enough to help Apple hit their 10,000,000 iPhone target by year end.
Expect vertical corporate software like Salesforce.com's iPhone app to proliferate quickly.
It will be hard to wait till July. But I expect to be seeing an ongoing series of Youtube videos showing off alpha and beta software to keep us going in the mean time.
Realistically, RIM can't compete with Cocoa touch as a development tool. Here's where the vaunted "desktop class" mobile software Steve talked about at the iPhone keynote in January '07 comes into play.
This is the joker in the deck. RIM talked about how playing media on a phone isn't that hard to compete with. Perhaps, but couple that with mobile Safari, core animation, OSX and a killer SDK and RIM, Microsoft and Nokia have something to worry about.