Honestly... I'm torn... which is surprising as i was all owww!!!! till i thought about it more..

I'm not hugely keen on mobs being used (especially ones that are aggressive at least), unless there is some sort of quest to save a young/raise one with it all..
It's going to look so crappy with loads of people standing around on different mobs i think..
As a Perk for Vets, maybe but then id like to see them linked to the GC's and areas they come from and limited but still.

I think i prefer everyone having chocobos, just seems right to me, an would look better.
Colours PonyBirds ftw really.. Give us enough armour and get the breeding minigame right and it'd be much better.