Cute. One problem, though: T-Mobile's network is not technically 4G. According to BGR, the International Telecommunication Union has already issued an official definition of 4G:
In this context, here’s what you need to know: for a service to qualify as 4G, it must deliver peak download speeds of approximately 100Mbps in high-mobility environments (cell phones) and peak download speeds of approximately 1Gbps in low-mobility environments. Current technologies such as WiMAX, LTE and HSPA+ certainly do not meet these criteria.
It's going to be years before cell phone companies have the capacity for what the ITU has deemed "4G." So with the holiday marketing season upon us, companies will do anything they can to get an edge, even if it means using the term "4G" in a way that renders it completely meaningless. TechFlash puts it best by saying that "rather than suggesting its rivals back down from their 4G claims, T-Mobile has decided to join them." BGR suggests that lawsuits will follow, claiming false advertising, but don't expect any telecom companies to change course: "Settling will be infinitely cheaper than rebranding. They’ve made their beds."