It appears from the live letter translation that they are taking Magitek Armor seriously as a mount based on positive feedback for it from us.

#XIVLive Q: What kind of other mounts will there be aside from chocobos in the future?

A: When we did a survey on the forums, we received a lot of requests for "Magitek Armor" as an example. Things like that will be a good reference going forward!
Since i have not seen a proper Magitek Armor thread going around yet. ...

That would be one very awesome mount.