AT&T has announced plans for a major expansion of its 3G wireless broadband coverage in 2008. The plans include expanding service to more than 80 unspecified new cities, as well as an enhancement in upload speeds provided by an upgrade to High Speed Uplink Packet Access (HSUPA) technology. The planned expansion is expected to deliver 3G services to nearly 350 leading U.S. markets by the end of 2008, including all of the top 100 U.S. cities. A…