Welcome to the newer, friendlier Motorola, where every would-be Android modder is catered to. After creating developer editions of both the new Droid RAZR I and Droid RAZR HD for Verizon (the first from the manufacturer-carrier combo since the XOOM) Google's new acquisition is spreading the love to AT&T. The company announced the ATRIX HD Developer Edition, complete with unlockable bootloader, via its Twitter account today. There's currently no price or date available, beyond the fact that it will be available soon.
If Moto follows its pattern with the Verizon phones, the ability to unlock the bootloader will not be made available to customers who bought their phones from the carrier, on-contract or otherwise.