Thanks for updating your site. However, the answer doesn't really address the dual-licensing issue (the choice of GPL or closed source) since it compares the GPL to closed source licences, whereas it should be standing up for the shared source "in due course" licence instead. We already know that paranoid device developers don't want to release their sources even, in some cases, when they've used GPL-licensed code. The answer doesn't address licence incompatibility or show that the "in due course" licence gives any particular benefits that outweigh the major downside of not being able to combine the code with GPL-licensed works.
As for the notion of relocatable modules, couldn't Castle just state, as the copyright holder, that they do not consider relocatable modules to be derived works of the operating system? I'm sure Castle managed to persuade various other copyright holders using a similar interpretation of the GPL when they squeaked through the alleged HAL "GPL violation" case. This time they actually have the authority to make that particular call, however.