My phones always come on UPS. Is it the same procedure?
I've never been OCD about this before, but I think you might have messed with my head.
Yes. All UPS flights do a stopover in Anchorage for refueling, as they do not run 777s. However, I would add to the OP's post that many eastbound 777s still do stop in Anchorage if they are fully loaded, which these planes undoubtably are. The only way FedEx is able to operate direct Hong Kong Memphis flights is by not filling the 777 to its weight limit. So it's more likely than not that your phone will stop in Anchorage for refueling, which is helpful to know if you are tracking it on Flight Aware (as the OP mentioned). UPS also has their major sort facility in Louisville, KY, whereas FedEx's facility is in Memphis. However, if you're on the west coast, UPS will likely unload your phone in Anchorage and put it on a west coast bound plane rather than flying it to KY and back.
If you want to see how the inside of UPS's air parcel sorting facility works, this is a great program (essentially it's the same for FedEx, too):
http://itunes.apple.com/tv-season/ups/id294286571?i=295191309
I do wonder, however, if Apple has pre-staged any iPhones in the US. When I bought the iPad 3 (pre-ordered on day of announcement) the iPad was already in the US and shipped to me from there, rather than coming direct from China. I have no idea if this is going to be the case this time. There are cost advantages with bringing everything over on a standard cargo carrier (versus a primarily small package carrier like UPS/FedEx) and then distributing everything from there. But when time is of the essence, it's faster to just package and ship from China.
I'm certainly part of the club that watches the plane bring my iPhone overseas, although I'm interested in air freight in general, so it's more out of a general interest in the area than needing to know where the phone is at every second. As I side business, I do some small package air freight from China to sell goods on eBay and Amazon, so gotten to know the systems pretty well.