Im glad you posted this thread cuz I was actually about to post a similar one myself. I have been using the droid pro for the past four months. Was actually given to me by a friend because they didn't like it.
Im due for an upgrade and kind of looking towards the droid 3. I've went in the Verizon stores and played with one. But I've gotta say a very huge drawback to me is the form factor. Even with the extended battery in my droid pro it is small sleek and very pocketable. The droid 3 on the other hand is massive and I just don't know if I can deal with that day to day.
The second drawback is the lack of 4g for me. Im not saying I need 4g right now. Cuz my area doesn't even have it right now. But if im going to be stuck with a phone for the next year then I don't want to be surprised in the next six months by 4g popping up and I don't have a phone to support it.
I am really hoping for a 4g pro 2 to come out in the next six months. Im just afraid that the lack of known audience for the droid pro will mean know droid pro 2.