Can't you use a "jailbroken" iPhone on Verison?
The real question boils down to what apps are avaialble for both that you might want to use AND how user friendly they are as a PHONE (oh yeah, that)
In my area AT&T is king, so iPhone would be OK for me (when my contract's up, I can't see spending more than necessary and I can wait 6 months). Verison's not bad here, so I would be interested in knowing how the Droid compares. I really haven't looked into it yet, though.