I ordered a Space Gray/256GB/1.3GHz on April 11th for delivery to CA. The status just changed to "Preparing for Shipment". My delivery window is listed as May 19-June 2. I was chatting with Apple support to correct an error in the associated email address and the person I spoke with said she thought I'd receive my unit towards the beginning of the delivery window. Here's hoping.
My Multiport Adapter is scheduled for delivery by Wednesday.
Update: I got a shipment notification and FedEx now estimates delivery on 5/15 by end of day.