According to PC World, AT&T has upgraded their HSPA+ network to 80% of their current coverage map. Unfortunately, the HSPA+ network is only accessible to AT&T's USB modems. So why haven't they come out with at least one HSPA+ device? AT&T might be holding out until their own LTE network rolls out. If they started making claims about HSPA+ 4G, they would lose marketing leverage when they launch LTE.
Then again, T-Mobile is also planning their own LTE network, but they are still cashing in on HSPA+ for the time being, with devices like the T-Mobile myTouch 4G. Perhaps as the nation's second largest carrier, AT&T isn't as prone to get into a marketing battle when their outlook for the war is so strong.
To non-PhoneArena readers, it probably looks like Sprint and T-Mobile have beaten AT&T and Verizon to the 4G punch. As the nation's top 2 carriers, AT&T and Verizon are in the unique position of delaying the gratification of new subscribers. Our suspicion is that by the time they start marketing their 4G smartphones, only a small portion of the general public will be committed to 4G contracts with Sprint and T-Mobile. Sales this holiday season should provide some perspective.
source: PCWorld via MobileCrunch