Not much has popped up recently in the way of pet-related news. Blizzard is extending its Black Friday/Cyber Monday sale until the start of next year, so if you're looking to RAF yourself for the pets, now is probably the best time to do it.
I'm still eagerly waiting more news/announcements on "pet breeding" and other Warlords of Draenor details, but that may have to wait a while. The holiday season is upon us, and while I have no doubt developers are working their butts off, I'm sure even they need some time to reflect upon this past year's accomplishments and stuff. Here's hoping we'll hear something about WoD soon! Maybe at the start of the New Year? :P
For the time being, a seemingly small PTR patch (5.4.2) was datamined and revealed a "new" Moonkin Hatchling. It appears to be the same as the current hatchlings from the Blizzard Store, however, its item and spell ID are unique and different.
This might be another one of those re-used pets for a unique event. A similar case would be the Spectral Tiger Cub and Spectral Cub. The former is from a TCG loot card while the latter is from a 2012 event in China. Although both have similar names and look identical, they are two completely different pets.
So it could be a situation where the Moonkin Hatchling pet is simply re-used. Or perhaps there's a unique place for this "new" version. We'll have to wait and see.