The way Metz does their flashes, is they manufacture a top unit that provides all of the flash functionality. This is then paired with an interchangeable mount, or shoe, that adapts the flash to a specific manufacturer's system. Eg. Canon, or Nikon.

One can purchase additional mounts to use the same flash body with multiple cameras from different vendors.. so in theory I could keep/reuse my flash if I switched over to Nikon cameras.. for the cost of a new mount/shoe. Not that I would switch at this point.

EDIT: I have had the firmware in the shoe upgraded twice since initial purchase, to help the flash implement the latest new Canon EX features. That new model appears to have a USB interface to make upgrades much simpler now. Great!

Cheers