The one thing I can think of in our favour is that "DLC", by its nature, doesn't require a retail distributor. So it'll depend on what resources Gearbox draw upon. If they deal directly with Steam and also distribute the content themselves, I don't see a problem. If 2K are involved it would be a more grim scenario. It would then likely require Valve and 2K to come to a workable agreement.
Alternatively we all hit up our good friends in other countries to help us out =p