I got my order on on 4/10 at 12:03 PST - at least that is the time on the email from Apple acknowledging the pre-order. And no, as of this evening my status has not changed from Processing Your Order to Preparing for Shipment.
I sincerely doubt if anyone will see that update until at the earliest next week. And even if they do ship, Apple's policy in the past for new releases is that the shipping company does not deliver before the release date. (Now I am sure that there are some stories about a mistaken early delivery - or perhaps a hefty tip to the UPS or FEDEX driver......)