You have brought up a very good question. In a way it's like the question many people ask: what's the best cell phone for me? The answer: the one you choose. No one else can choose for you. It's up to you to decide what you want in features, functionality and the price you are willing to pay for those features.
Just in case you didn't know what convergence is, it basically means that you will be using just one device instead of both. But otherwise, read Archer's post as he is spot on. Although the iPhone is a cool device, it is not for everyone. Make a good, educated choice by watching the keynote, reading more about it, and thinking about what you really want to do.