More confusion between these terms -- and with 4G in general -- is that companies tend to throw them around as marketing terms that may or may not mean anything.
Case in point -- the iPhone 4S. That started out as a 3G device, but AT&T decided to get cute and claim they ran on a 4G network. But, what made that network any more "4G" than the "3G" one that the phone used? AT&T was somewhat silent on that point as it appears that using the term 4G actually sold phones whether it actually meant anything or not.
There needs to be some clear cut standards when it comes to wireless communications speeds. We may be getting to that point, but there is still some work to do.