Thinking of replacing your land mount for a flying mount? It wouldn't be a faster than your wolf or your raptor. What it would do is give you access to "hard to reach" areas. And by "hard to reach," we don't mean the small of your back. We mean some key locations that are only accessible by flying mount. Blizzard's Drysc explains:

We fully expect you to continue to use your epic ground mount while on land until you move on to an epic flying mount. The normal flying mount (aside from offering you access to otherwise unreachable locations) provides enough perks for the comparatively small investment that we don't feel it also needs to completely replace your ground mount.