There are lots of reasons to get the iPhone instead of the Blackberry.
Who would want an actual keyboard to get actual work done? Trust me - you'd much rather have a touch screen. Just like those airport checkin machines that won't quite get your mileage plus number right no matter how many times you press that 4 key.
Replaceable batteries are for the same sort of people who back up their hard drives and make backup plans when they travel. Why would you want the ability to swap batteries when you wear one out? Why wouldn't you want to take up an iphone sized space in a landfill when the battery quits for good?
The iPhone 3G's dropped calls are really cute, just like when a baby poops its mom says "but they're the cutest poops!"
You won't ever want to send MMS messages. Apple knows so. They took out the ability so you wouldn't even be tempted. Which is fine, until you want to send a picture to someone with a regular phone. Oops!
This is the reason they neutered the camera so you have to hack it to take video. That is an overarching theme with the iPhone. You really wouldn't want a boring old blackberry where everything works out of the box when you could have a super cool beta phone where everything you want to do requires you to hack your phone.
When you have an iPhone you can show off your cool apps like the virtual lighter for when you forgot your real lighter at a concert. Or maybe that virtual leveler. These apps make your iPhone much more useful than a blackberry. I'd take things like motion sensitive drinking games over efficient data compression and low network utilization for better battery life any day.
Steve Jobs told us we want iPhones. He wouldn't lie to us. He just wouldn't. Like when he said I wouldn't ever want copy and paste! He knew it before even I did! He's my hero. I'll buy anything he puts out.
Reason #1 to get an iPhone. Two words, repeat after me. Class Signaling.
Edited to add: In case you can't tell, I took a pass on that adorable little touch biscuit and got a Bold.