Iceweasel is the latest firefox
Debian unstable now has iceweasel.
Running iceweasel presented me with the pretty message
You’ve Updated To The Latest Version of Firefox
Great.
Note: Ubuntu has more patches to firefox than Debian, so if Debian is (or: was) violating Mozillas trademark, so is Ubuntu. And probably Fedora. And Redhat. And Gentoo (well, maybe not; from what I know Gentoo is closed to unmodified upstream usually, and not as anal about LSB and desktop integration etc. as the others), … you name it.
Anyway, go, iceweasel, go.