Apparently that marketing ploy is working.
It's bloody brilliant in my opinion. They barely have a LTE network and yet people already believe they have one that is bigger than VZW because the iPhone 4S says "4G" instead of "3G" on their network.
Personally I would like to see the FCC hammer AT&T for this. But sadly because the LTE rights holder gave AT&T permission and it technically doesn't break an federal laws, they can't touch it.