I also have an Alltel touch pro & the verizon merger will be complete in my area on 12 July. Verizon just sent me a package in the mail explaining the changes. From what it says, the switch to verizon will be transparent...phone & voicemail will be the same. You will still be able to receive txt messages at your "phonenumber@message.alltel.com" address, but will also be able to receive them at "phonenumber@vtext.com". The only thing I can't find info on is if data/mms will change. I'm assuming that will be transparent also, otherwise it will be a customer service nightmare for them. Guess I'll find out next weekend.
Now I just have to decide if I want to switch back to my Omnia after the merger. That was my intention all along, but I've gotten pretty attached to my touch pro. Nice phone once it's flashed and tweaked. I've also gotten spoiled with the hardware keyboard, don't know if I could go without one again...decisions,decisions.