Easy, T-Mo subscribers, Lil Wayne is on his its way to help your MiFi cause as early as March 2011. Or, at least, a leaked screenshot hints this is the case. This first portable router by T-Mobile, which seems to be hilariously codenamed Lil Wayne, is set to be followed by another T-Mo-branded mobile hotspot in the second half of 2011.
21Mbps and it will be branded a "4G router". However, no information about the two devices' manufacturer(s) and prices is available, let alone any indication about what kind of data plans the fourth-largest US carrier will offer.
As for the bigger MiFi picture in the US - Verizon and Sprint already have MiFi devices (for over a year, actually) and one more for each CDMA carrier is coming as well (namely, Sprint's Novatel 4082 and Verizon's Samsung SCH-LC 11). AT&T only recently launched its first MiFi hotspot, which offers faster speeds than its rivals and an own OS, but also more expensive service plans.
source: T-Mo News