Why would anyone be fucked? If he has any issues with KMS on R200+AGP+PowerPC, he won't upgrade to Mesa 7.12. Plain and simple.
Besides, Mesa 7.12 will be able to load 7.11 drivers too.
I for one would be sad if those alternatives went away. I am a happy Arch Linux user but I think that it is important that there are other independent alternatives (I am personally playing with Plan9 but I am still far from being able to use this as a primary OS), like the *BSDs and the solaris-derived (now illumos-derrived) distros.
What I would like to see is actually *more* diversity on the Linux side - we already have the "kFreeBSD" variants of Debian and Gentoo, and the nexenta illumos/debian hybrid. As far as I am aware, there are no non-GNU Linux OSes (BSD or Solaris-derived userland) out there....