As goes Debian, so will likely go *buntus. And Mint, too. And something about the concept of switching to another libc just seems to have Fedora's name written all over it, too.
Unlike with the XFree86 situation, the *BSDs won't continue to use glibc for years afterward, because they've never used glibc in the first place. Ulrich and his project could become irrelevant remarkably quickly if Debian really goes through with this.
Hopefully also unlike the Xfree86 situation, we won't spend years waiting for some big architectural overhaul to be completed before the real progress can begin.