A crescent moon mount would be cool:



Not in the flamboyant anime style though, but a more elegant FFXIV one.

I also like two seater mounts, would like a lot more than the wedding chocobo/mogstation moogle/mentor pegasus.

A long and sinuous dragon mount would be nice too, I like leviathan's shape:



A mount where some guy runs you around on his shoulders would be pretty funny too.

There's also the idea of an aztec style stone mount:



I rather like the idea of being driven around in a carriage like former idea showed.