Not One, But Two
And yes! You read that right; hatchlings. There will indeed be an alliance and a horde version of the adorable balls of feather and fluff.
It is still unknown whether or not the alliance and horde versions will come from separate items or a single item that changes depending upon your character's faction. If the former is true, there is also the question of whether or not players will be able to learn both hatchlings on a single character, or will each version be faction specific like the Argent Squire and Argent Gruntling. We'll have more details on the Moonkin Hatchling's pet profile after its release.
Animation Preview Videos
Right after we posted this blurb, MMO Champion posted two adorable preview videos on YouTube. Check 'em out!
Now if those aren't "awww"-inspiring, I don't know what is!