I don't think there will be a shortage. It's going to be available on all major carriers, and I think the days of lining up at 5:00 AM in front of a VZW store for a phone are over. Verizon released the Nexus and Razr/Razr Maxx all with 6 month ago, so a lot of customers are locked into those contracts.
I'm not going to pre-order. I want to hear some feedback on the phone after it's been out for a week or two.