According a report from OFB's Timothy Butler, AT&T has been boosting its 3G coverage and signal strength over the last few months; however, the upgrade is at the expense of its 2G client base.  Company technicians have confirmed to OFB that they have been switching 850 MHz 2G repeaters to 3G service and using the weaker 1900 MHz repeaters as replacement.  This has already left some 2G users with reduced reception and weaker signal in previously strong areas. 

With a sizable portion of its user base still on 2G devices, which includes the first generation iPhone and many Blackberry models, it's hard to believe AT&T would transition users so soon.  If its plans are indeed to force users to migrate their devices to the newer 3G protocol, it would not be the first time.  A similar tactic was used to migrate users from TDMA to GSM in the early 2000's.  In March of 2006, AT&T formally announced that the TDMA network would be shut down by February of 2008.

Another issue arises when you consider the potential of new subscribers who are locked in a contract with no way to purchase a new 3G device at a discount.  If your new Blackberry suddenly sees a drop in reception and reliability because of a change in network coverage, you're left to deal with the issue or purchase a new device out of pocket.  When OFB contacted AT&T's customer service department they were at one point offered a $200 hardware upgrade credit for a new 3G device, which is fairly standard practice for carriers to offer clients that are nearing the end of their term. 

AT&T’s executive director of analyst relations, Mark Siegel, has denied these responses as official company policy.  There is no concrete evidence as to where and how many towers are being changed over but according to OFB, other similar reports of decreased data performance were found across the U.S.  However, the reality is if 2G doesn't work where you need it, you have no choice but to move to a 3G device or switch to another carrier.