This morning, AT&T took the wraps off its plan to upgrade 3G in various markets across the US this year. By various markets, we mean exactly six. HSPA 7.2, or High Speed Packet Access capable of providing downlink speeds up to 7.2Mbps, will theoretically provide a tremendous boost to AT&T’s 3G network speeds ahead of its eventual 4G rollout. As you may recall, Apple’s iPhone 3GS handset is HSPA 7.2-ready and owners have been waiting impatiently for word on when they might actually be able to take advantage of the higher-speed data services they were promised. Unfortunately, unless you live in and around Charlotte, Chicago, Dallas, Houston, Los Angeles or Miami, the answer is still unknown. The six aforementioned markets are due to go live before the end of 2009 and AT&T claims another 19 unnamed major markets will go live by the end of 2010. The majority of AT&T’s remaining 3G footprint is slated to be upgraded by the end of 2011 — while many are (hopefully) already enjoying LTE. So to AT&T customers in the six markets listed above, congrats. The rest of you will unfortunately have to make due with what you have in the meantime.