WowInsider posted a video of what it will probably look like since the version in the PTR Pet Journal is merely the Anzu boss model. It still resembles the Raven Lord and shares strikingly similar body structure to the Ji-Kun Hatchling, but you can't deny that it's absolutely adorable.
You can also check out a video preview of the Dread Raven Mount in the WowInsider link as well. It appears to be a combination of a protodrake, skyscreamer and Anzu. There's already a mount that you can acquire from the Raven Lord himself (heroic Sethekk Halls only), but unfortunately that mount does not have the ability to fly while I'm guessing the Dread Raven will.
Wain from WarcraftPets brought to my attention something interesting relating to the original "raven mount", a spell called Dread Hatchling Love Trigger. If the spell name is any indicator of what it may do, it sounds as though the Dread Hatchling will "love" (floating hearts over its head?) the mount version of itself. Interestingly enough though, instead of interacting with the new Dread Raven Mount, this love spell is tied to the original raven mount. It's possible that this is to give a small nod to mount collectors that have obtained the original version, so as to not take away from their achievement and prize.
On the battling side of things, LeCraft Tweeted a teaser of the hatchling's abilities and stats. I'm not a battling expert so I can't comment on this pet's potential, but it does seem to have similar moves to the Gilnean Raven and Crow. With so many healing comps running amok in PVP, another counter is probably be appreciated by the battling community.
I'm pretty eager to get my hands on this cute little birdy, but will have to wait since a release date hasn't been announced yet.
It's curious to me how the WoD CE pet is essentially a baby Anzu, so I'm wondering how that ties in with Draenor. Did the Raven Lord come from there? Are there other creatures similar to him wandering around the draenei world? What significance does he have in the upcoming expansion? I can't wait to find out the answers!