It doesn't matter what that email says. This happens with every single Apple release. There are always tracking numbers, emails, confirmations with people at FedEx and UPS; and guess what? No one gets anything until release day.
True in the past, and I experienced the same with the 3GS. But I believe this year is different. Apple was very specific in the email. It seemed like they were making the point to say "it's coming a day early, so make sure you're there to sign for it or pre-sign now".
I'm therefore expecting to prove you wrong sometime tomorrow. I'll post pics when my shiny new gadget arrives.