The Linux kernel is under the GPL version 2. Not anything else. Some individual files are licensable under v3, but not the kernel in general. And quite frankly, I don't see that changing. I think it's insane to require people to make their private signing keys available, for example. I wouldn't do it. So I don't think the GPL v3 conversion is going to happen for the kernel, since I personally don't want to convert any of my code. You think v2 or later is the default. It's not. The _default_ is to not allow conversion. Conversion isn't going to happen.