The tooltip for the mount says "Skill changes depending on your location." This means it will be a ground mount and flyer along the lines of the pet store mounts.
That being said, because of this I doubt it'll be a cloud serpent mount. Those things are HUGE, and people already gripe about the big obnoxious Heart of the Aspects flapping around in Battlegrounds. Plus, the basic models are already confirmed as daily rewards, and the god serpent mounts are probably too exclusive to risk oversaturation by being purchasable.
If it was an altogether new model, I'd be so psyched.
We still need Roc and traditional Pegasus mounts. I can't believe those don't exist in a world where we fly 80 different types of dragons, gryphons and their cousins, wyverns, and robotic gnome heads.