AT&T offers specifics on its HSPA+ upgrade and LTE deployment: At CES today, AT&T released its timeline for rolling out 4G LTE mobile service, which launches in mid-2011. Verizon Wireless gets bragging rights with several markets lit up in late 2010. However, with few devices, and an odd pricing model for such a fast service, Verizon has very little lead over AT&T.
AT&T and Verizon will likely both complete national urban rollouts by 2013, the stated date by both firms now for that goal. Their various FCC licenses require either geographic or population based completion at four and eight year targets, which will drive LTE service into less-populated areas and small-to-medium-sized towns.
AT&T's current HSPA/HSPA+ network is also measurably faster than Verizon's, which cannot increase its 3G speed at all. AT&T, like T-Mobile, is taking advantage of baby steps with HSPA (to 7.2 Mbps) and HSPA+ (to 21 Mpbs) to have an interim advantage, as well as a better hybrid 3G/4G roaming experience. Verizon is stuck at EVDO Rev. A, about 3.1 Mbps downstream. (All those rates are raw, and Verizon's coverage area remains superior to AT&T's; HSPA+ doesn't offer an advantage if you can't actually pick up a signal.)
Of course, it wouldn't be a telecom announcement without having to pick apart some news. AT&T says that it has HSPA+ available to "virtually 100 percent of its mobile broadband network" but then notes it requires "Ethernet or fiber backhaul." It predicts 2/3rds of its HSPA+ footprint will have such "expanded backhaul" by the end of 2011.
Which means that at the beginning of 2011, substantially less than 2/3rds of AT&T HSPA+ network cannot deliver true HSPA+ speeds, being constrained by the backhaul. If it were more than half, you can believe AT&T would have stated that in the press release.