My Verizon upgrade is next month....android or iphone
Try both and see which one you like. A lot of people don't realize that you can return the phone for up to 30 days. They will attempt to hit you with a $35 re-stocking fee, but you can generally talk them out of it, especially if you're going to try a new phone.
I like my Droid X, mostly being that it's the best browser/screen size combo for me to use at work. I like Android, but it took about 3 weeks of real use to customize the phone to get it to where I want it. I think it will be even better once/if the Gingerbread update arrives.
But, the thing about the iPhone is, everything generally works the way it's supposed to, and is a very seamless, slick user experience. You won't get some of the minor bugs/hangups that you get with an open sourced format like android. You won't get the flexibility either (I'm going to assume you're not going to jailbreak/root you phone like someone will no doubt suggest).
I don't think you can go wrong either way. Personally, I'm going to wait for the next iPhone on Verizon.