I finally got through at around 9:30 PM Eastern. No confirmation email or temporary charge on my card yet. However, I did order the dock in a separate order much earlier and I've already gotten an email confirmation and full charge regarding that.
When the mess was going on this morning, I downloaded the Apple Store app and did the reservation for my local store. I guess to be on the safe side I won't cancel my reservation until I get my confirmation email for the preorder.
EDIT: Sweet, just got my email confirmation for my preorder...and it's marked with a 6/24 delivery date! Yay! So relieved.