mmo-champion and wowhead both have news from the PTR for 4.2. four new pets have been discovered:
- feline familiar (bind on pick up)wowhead is reporting that the last one, the whelpling, will be the guild reward upon completion of the new legendary weapon.
- fire lasher (bind on use)
- hyjal bear cub (bind on pick up)
- dragonwrath whelpling (bind to battle.net account)
it's not 100% clear where the other three will come from, but the name of the hyjal bear cub is probably a strong indication that it will be from hyjal or near/around that area. there is currently a quest involving the little bear cubs, so it's likely that this companion will either be the very same creatures involved in that quest or very similar to them.
the fire lasher sounds like it will be from the new daily quest zone, featured in 4.2 but we will have to wait and see.
the feline familiar... well anyone's guess is as good as mine on this one!
UPDATE: wowhead has neat 3D models of what might be the guardian cub and feline familiar(s)!