Yeah, in the original JK1 plan, Kell Dragons were going to be ridable by enemies (Grave Tuskens IIRC) and there would also be a beat-up looking Swoop bike you or enemies could ride!
MotS also had some unused "speeder models" (though I'm not sure if they were like Landspeeders or speeder bikes).
So it wasn't until JA that we finally got those long lost dreams of ridable animals and bikes! But yeah, a Kell Dragon vehicle would be great!
PS: Found a pic of a re-creation of the JK1 style speeder bike!
It's downloadable from Massassi.net in the MotS 3DO's (3d models) section, as speederbike.zip!