I have just checked in My Orders on the Apple website and I now have a tracking number and the name of the carrier (UPS).
My estimated delivery date has changed from 23 Jan to the 22 Jan

One thing that concerns me is.
In My Orders I have three items shown:
iMac
G-Technology 4TB G-DRIVE external hard drive
Apple USB Super Drive.
Now when I go onto UPS and track with the tracking number I have been provided, it shows Total Packages in this shipment 2.
I'm just wondering if the Apple USB Super Drive is in the box with the iMac, or perhaps in a larger box along with the G Technology external hard drive. Has anyone ordered similar or the same as me who can say if this is the case?
UPS site tells me that the weight for the packages is
Package 1= 14.10 KG
Package 2= 2.70 KG
2.70 KG seems a bit too light for a box containing both the Apple USB Super Drive and the G-Technology external hard drive though?
Update:
I've just checked the weight of the Apple USB Super Drive and the G-Tech external hard drive that I'm getting on the Apple website, and the weights are as follows:
Apple USB SuperDrive= 335 grams
G-Tech external hard drive= 1300 grams
Total weight then been= 1635 grams
So the additional 1.1 KG or so will be the packaging. So I'm pretty certain that the Apple USB Super Drive and the G-Tech external hard drive will come in one large box. So the 2 packages is correct.