I just got a notification the phone is shipping. They shipped it ground.
Are you getting it from Apple, or a carrier?
If this is from Apple, this is what I've noticed in the past with some of my orders:
If it's in stock in North America, and you choose regular shipping, they may ship it ground. You get air only with expedited shipping.
However, if it's NOT in stock in North America, and it's a hot new product, they will often ship it by air directly to you from China regardless of what shipping method you choose.
IOW, an in stock item in North America might take 5 business days to arrive, but a directly shipped item from Cina might take 2 business days to arrive, even if both are ordered with regular shipping.