I think it will diverge some more, and someday the friction between the distros will be similar to the friction we now have between Linux and other Unix (like)-OSes. We have seen the Linux-only development way, now some things start being specific for one distro (upstart .vs. systemd f.e.) and since packages of applications need to interface with it in some cases we may see the applications diverge as we see the drivers for Xorg today.
Then someday will come the day when there are real forks from the kernel, and they will diverge until no code can be shared easily. There will always be something there to continue, but it will no more be Linux-as-we-know-it as the modern man is the same as the version from 1 million years ago, or will be in one million years.
This is evolution, but sometimes evolution creates things which cannot continue (see sabre tooth tiger), and then it is time to re-format and re-install.