iTunes though doesn't have to be installed on everyones machine for an iPhone to work in a corporate environment. It just needs to be activated once. Then IT can manage the device in a similar way to Blackberries. Configuration profiles and certificates can be loaded to secure the device, and updates can be pushed over the air.

I know, logic doesn't always work with the IT or security departments at these places, especially when as you said, IE 6, one of the most security vulnerable browsers around is still the standard browser in the organization.