Mark Shuttleworth wroteFor all of our sanity we are going to try to keep these names alphabetical after Breezy. We might skip a few letters, and we'll have to wrap eventually. But the naming convention is here for a while longer, at least. The possibilities are endless. Gregarious Gnu? Antsy Aardvark? Phlegmatic Pheasant? You send 'em, we'll consider 'em.
This seems to hint at suggestions #2 or a variant of it. They'll still have codenames but with a different pattern.