Wow, this thread is impressive. I'll admit that I'm not accustomed to seeing the official posts on this site being so filled with marketing speak as this one, but I'm more amazed at the responses. Not since the Netware days have I seen so much technology-bigot talk. It become fairly apparent that most of these responses come from people so deeply entrenched in technology that they can't actually see the business needs that they are employed to fulfill.
Nothing is ever this black and white and neither of these technologies is the be all/end all for the business world. They are simply tools that each company has to decide on the benefit of before deciding to deploy. E-mail and collaboration have huge benifits to business. At the moment, IMHO, the iPhone is more hype than tool at the moment, but I know that will change as people adapt to it to business environments. It has huge potential for business use, but at the moment it's not nearly as cost effective as other solutions. That will change, however.
The solutions I deploy don't have to be the most pure choice available, they have to be the best solution for the business for the cost, regardless of vendor.