GBristow: Wait for the fourth generation iPhone. You'll see a price drop with the current models, if you're that way inclined, and the 3GS and newer iPhone will come with the iPhone 4.0 OS. It'll allow multitasking to a degree, folder organisation, and more than one exchange profile.
Hi GBristow. Yup - definitely waiting for the 4th generation phone if I do make the move.