The intrepid folks over at Wowhead
have continued to dig up tons of pretty cool new files and models from the patch 5.4 PTR. New mounts have been added to the files -- three new armored cloud serpent models, presumably for PvP participants, and the Stormcrow
mount. Along with the now-familiar red and gold varieties of cloud serpents shrouded in intimidating armor, there's also the gorgeous onyx variety pictured above. While there aren't any details yet on how these serpents will be obtained, it's safe to assume that they're PvP related, as pretty much all of the PvP reward mounts have been armored versions of current expansion models.
As for the Stormcrow, Adriacraft
has a video of this impressive steed in motion. It bears a resemblance to the Reins of the Raven Lord, but unlike poor Anzu, this bird can fly -- and it's got crackling lightning aura to boot. While there is no news at all yet on where this unique mount will be obtained, it doesn't seem to be related to the Siege of Orgrimmar at all. Perhaps a lost relic on the Timeless Isle? A new pet store mount? Only time will tell.