As I've said before, once Linus is gone, we might well end up with splits at the kernel level rather than at the distro level. And we would be wise to avoid any one organisation's stock kernel, even if there are some very large organisations providing a lot of code for the kernel at present. I can see a future where, say, GNOME, start producing their own kernels to support their vision of the Linux desktop from the ground up. And it's all but certain that Canonical and Red Hat would be very interested in things going their (respective) way(s) when the time comes.