I got this email too, and my FedEx tracking agrees with the June 23rd delivery date. I'm excited if this is true. But, is anyone concerned about the mistakes in the email?
Title: "Your iPhone will deliver on June 23rd" instead of, "your iPhone will be delivered" or "will arrive" or something more correct.
Also, in the body of the email: "you can check the FedEx website the morning of the June 23rd". Why "the" June 23rd? Also, no link to the FedEx website.
I'm probably reading way too much into this, I just couldn't help noticing these strange mistakes. Perhaps the Apple Store Team is just a bit overwhelmed at the moment.