Granted, 56 cards isn't much of a launch, but if XFX got them in that quickly, its not too far-fetched to think that other board makers could be supplying very soon(Powercooler, HIS, MSI, etc...). As it stands, 56 boards isn't a wide release, just meant to spoil the release of the 560 ti.
I do find this marketing tactic very similar to what Nvidia pulled with the 460 FTW during the 68xx launch. All reviews site took quite a bit of heat with that one.