Well it has 400 MIPS so it's pretty obvious it won't conquer an i7 for now at least. In embedded things it might have a use, but I don't know if Debian is the right choice for embedded devices. I thought that embedded devices based themselves on a different 'distro' of linux. Can't remember the name right now.
Debian aims to be "The Universal Operating System" and IMHO they have succeeded fairly well.
Debian is one of ~2-3 major freely available projects that provide ports and patches to make software run on minor architectures; referring to the Debian packaging, source mirrors, and patches can be a real help even if you build from scratch.
Regarding m68k vs i7: how fast does an i7 emulate m68k (remember what I said about Atari emutors), and how does it compare at that for power efficiency?