AT&T not selling BlackBerry Bolds until Dakota arrives
This situation may change soon, though, since some rumours point that we are set to see the launch of the BlackBerry Dakota (believed to be the next Bold) as soon as early spring, although significant numbers of this phone are not expected to grace AT&T shelves before "very early summer".
Whether this is the reason only a small quantity of Bolds are available in the AT&T stores at present, or the second-largest US carrier is simply clearing out the dead wood, is up to debate. The BB Dakota is set to offer a 2.8-inch screen with a resolution of 480 x 640 and BlackBerry OS 6.1.
source: Fudzilla via BlackBerry OS