Does 4G exist?

Short answer from a telecom employee; No. It does not in fact really truly exist... yet.

Everything labeled 4G today is "expected" to conform to the next standard but really is more of a "may conform to if it goes the way we think it will".

This. Adding to this, the "4G" today is actually only in a select few cities at this time. Also, this "4G" is only in small parts of those locations.

Surprisingly, I'm in Rochester which was selected as one of the 38(I think) cities initially chosen. I plan on upgrading soon to one of the 4G phones. Also, LTE (Verizon's 4G) is what is heavily being looked at as the standard for 4G, from what I understand. I could be wrong about the LTE.