This is what I've come up with:
iphone pros:
-visual voicemail
-larger screen
-app store
-smoother web browsing
bb pros:
-cut/paste
-integrated turn-by-turn directions
-mms
-expandable memory
-tethered modem capability
-my choice of carriers
-3rd party app support
-camera has flash, video, zoom, and self-portrait
-i can change my own damn battery
(a lack of these on the iphone is just pure stupidity on apple's part)
These arent all the differences, obviously, but they're the ones I've found that matter to me. Looking at comparisons, the biggest reason people seem to go with the iphone is "It's APPLE! DUH!!" while those who prefer the BB actually have good reasons for it. Apple knows this, too - they know they dont have to try very hard. People will line up overnight for anything Apple-related. Blackberry, otoh, knows it has to compete. (on a slightly related note, if I didnt already have an ipod, I'd seriously consider a zune)
I'm kind of torn, but I care more about the features the BB has that the iphone doesnt. I can live without what i listed for the iphone.
I think at the very least, I'll be waiting for the BB Bold to come out before deciding. Especially to compare pricing and speed.