[jrockway]

I'm not sure they have the choice about whether or not to GPL it. They are building on GPL'd code, which means their code must be GPL'd. Perhaps there's a formal way to say, "we won't go after you if you use our code against the terms of the GPL, but we can't control what Drupal does".

[protomyth]

or they can't use GPL software because of the license....

They really need to obey the law and should have an actual statement about how this works.