The iphone is a great device, but will not replace the BlackBerry as a business tool. As someone who deals with BlackBerry’s everyday, there is no fear in the business sector of the iphone taking any substancial business from RIM. There is a great market in the retail and casual user side that iphone markets well to, but as a business tool, it is still lacking. IMO.
Aside from 3G, which has less than 4% coverage in the US, where is the iPhone lacking as a business tool that cannot be answered by third party software? Have you actually used an iPhone?