[Used Can]

Hmm... I don't know. I loved Last Exile, but the story seemed properly concluded. So, I honestly don't see what they could do, unless they go for a prequel (and even then, we've got enough information to know what happened).

This is one of those situations in which I simply liked the show so much, and in which I believe the show was so well done and properly ended, that trying to do something else with it has high chances of ending up in disaster.