Children's Week is here!
If you haven't yet gotten all the pets, then now is the time to escort that orphan! And if you HAVE gotten the pets, there's something to sweeten the deal in making the various orphans run you about Azeroth & Outland - there's a new bag option in the rewards. Of course, there is still the Curmudgeon's Payoff! But there is now a Pet Care Package, and it can contain Perky Pug costumes, Lesser Pet Treats, Pet Treats, the pet-size changing items, and a Flawless Battle-Stone! It looks like the latter is always in the bag, and remember that's the one that is unbound and can be sold or traded. I noticed on my server the price of the stones dropped by at least 2k in just a few days, so if you don't want to use it, I'd suggest keeping them around until after Children's Week is over to get the most bang for your buck.
And remember that as long as you're high enough level, you can do this on alts (level 10 required for the one from vanilla, 60 for the Outland one, and 70 for the Dalaran one), so you can get ALL THE PETS if you don't have them, as well as as many stones as you want to escort orphans for.