My point is that as time goes by and the gplv2 tool support is picked up by someone else it would diverge from the gplv3. If the kernel is written for the gplv2 branch of the gnu tool set the gplv3 branch wont work with them. The library calls will begin to differ. If you dont believe me go ahead and try running the kernel from FC6 on the gcc libraries of FC4 (about a year old). Let me know how many bad returns you get from calls by the kernel to those libraries.
The only ways for FSF to make their own linux (long term) could be:
1) They copy changes made to a gplv2 branch into gplv3, this would be no big deal because there would not be two versions of linux just two licenses to choose from.
2) They write their own kernel for gplv3, they would need Linus's ok to change the licnese on his work. They would also need his permission to call whatever they did 'Linux'. Finally the FSF and stallman have shown while they write nice tools they cant do the os.
3) Linus goes along with GPLv3, will only happen if the anti drm stuff is trimmed out of the license and then this discussion is academic.
That's really going to piss off Stallman when he's finally done with the HURD kernel. It'll be out there, but almost nobody will be using it except for a small group of hackers who generally try anything, and his hard core supporters.
It will not have the name recognition of Linux, and while the code may be free (as in speech and beer), the trademark isn't (not in speech and only sometimes in beer).
BS, Stallman's GNU environment has even been ported to the Solaris kernel, called Nexenta, if any porting is even required to the Linux kernel it should be even easier.