While it puts the finishing touches on its nascent 7.2Mbps upgrades and starts certifying devices to use it, AT&T has revealed a juicy tidbit: that's probably the end of the line for old-guard HSPA on the country's largest GSM network. Before LTE, though, AT&T plans on upgrading to HSPA+ which should bring 21Mbps speeds out of the gate; straight-up HSPA is theoretically capable of moving to 14.4Mbps, but AT&T says that it's had technical difficulties in maxing it out and HSPA+ equipment is now ready for implementation anyhow. Simultaneously, the company says it's adding additional
