I surely doubt it, many people have pride in the mounts they've collected and I'm certain they'd want to be able to use them for every race, the day I was allowed to use my gnome mount as a human was a great day.
---------- Post added 2013-02-21 at 09:06 AM ----------
Not sure if trying to be funny or just bad, either way, nagas will most likely never be playable and will certainly not "slide really fast"