Theoretically, HSPA 7.2 gives a maximum download speed of 7.2 Mbit/sec, with average speeds double of what AT&T can now offer with conventional 3G, de la Vega said. Presumably, an Apple tablet could take advantage of HSPA 7.2, but it is not completely clear that's the case.

However, theoretical speed is largely meaningless, especially to end users, Gold and other analysts noted.

Root Wireless found in a recent study that ranged from 246 Kbit/sec in New York to a high of 428 Kbit/sec in Dallas. Also in that study, Verizon offered average 3G speeds from 195 Kbit/sec in Seattle to 259 Kbit/sec in Chicago.

If users decide to connect to a cellular wireless connection, they will have the variations of distance, the number of other users and physical obstacles, just as they do today with cellular voice services.

If they work within a Wi-Fi network, as the Apple tablet is rumored to support, speeds of 10 Mbit/sec up to more than 100 Mbit/sec is possible, but only within that network.