New Pet Sounds
Currently there are many companions on live servers who do not have any on-click vocalizations. However, there is a list on the Petopia Forums of vanity pets who have suddenly found their voices on the PTR. It will be interesting to see if these new pet sounds go live. I'd love to hear my Cockatiel finally make some chirping noises. For a bird, he's way too quiet!
Zul'Aman Change and Mojo
With the changes to Zul'Aman, many collectors are wondering if Mojo will still be available post-patch 4.1. At the moment there aren't any clear answers as to where and how Mojo will be acquired after 4.1 goes live. If you are seeking to solo-farm Mojo, now would definitely be the time to head out to Zul'Aman and pick him up.
We don't anticipate Blizzard removing Mojo completely, as they have shown their commitment and desire to keep the old school minipets in-game. However, much like a few companions were displaced during the old world revamp, we may have to simply wait for Mojo to be relocated if he's not found within the updated Zul'Aman instance post-patch.