Well this is a bit out of left field -- Motorola has announced it will be selling an Atrix HD Developer Edition. The Droid RAZR HD Developer Edition just went on sale a couple weeks ago, and it looks like the Atrix HD will be following suit. Motorola doesn't give any price or availability -- assume its going to be expensive and coming out later -- but an official announcement is good nonetheless.
As part of the announcement, Motorola also seems to imply that the original Atrix HD is going to be part of the developer program that gives bootloader unlock tools to willing hackers. If true, this is probably more important to most users. You have to assume that most people who were interested in an Atrix HD have already purchased one and wouldn't be interested in buying a completely new handset. Unfortunately the bootloader unlock page still doesn't list the Atrix HD, so we can't completely confirm that this is the case.