Thanks guys. I'd been trying to call my Apple store, but no one picked up the phone.
Just in case, I'll have enough documentation to buy a home.
I love the upgrade possibility. I'm going early. Would like to turn my 32 into a 64 I think. We'll see.
Confirmed: all you need is to know your Apple ID. They will have a list and will be crossing email addresses as people get their iPads.
Also, if the walk-in stock permits it, you will be able to change your reservation to another iPad. If you reserved one iPad, you can get another if you want, if there's enough stock from the walk-ins that is.
Confirmed this at the two Apple Stores in St. Louis.