They are offering the LG Optimus T for T-Mobile ($10+ data plan required), the Sanyo Zio for Sprint (Everything plan required), and the Motorola Flipside for AT&T ($25 data plan required). On top of that, they will throw in a free Plantronics Explorer 240 Bluetooth headset.
The free headset is only available on in-store purchases, so it might be worthwhile to venture outside for this one. We know you might be holding out for a Sprint 4G device, or maybe a T-Mobile G2, but all of the sale-item devices are more than capable. If your heart is set on another device, remember that RadioShack offers pretty fair value on customer trade-ins. 'Tis the season for saving money.
source: RadioShack via AndroidGuys