As a former Starbucks employee, I can say it depends on where you got your coffee in the US.
Most stand alone stores in the US use the same cream as they do here, actual cream in a aerator can thing. However, in the stores that based in Barnes and Nobles, and some other shops, they use the normal readi-whip type stuff.
I worked in a B&N and was constantly reassuring people that we did not use real whipped cream and it was low fat. Lots of people didn't want the full fat cream. I am not sure why we didn't use the full fat stuff, just that I was told none of the B&N store shops did.