no impact as far as I can see. Knoppix depends on Debian(be it unstable or testing or stable). The latest X11 on debian is 4.3 which is before the fork. Given the time it takes to make 4.3 works on all debian supported platform, it would be a long while before the XOrg fork can enter debian. Debian based system would be stucked with 4.3 for some time to come.