So what exactly am I talking about?
An unannounced change was made back in 2011, where stealthing with a companion out would also cloak your pet and hide it from other players' view. It would still be visible to you, but from everyone else's point of view, both you and your pet pretty much disappear.
In MoP, this still works for both druid cat form and rogue stealth (I haven't tested Mage invisibility or Hunter camouflage). But add a new step to the equation: entering a Pet Battle, and you've got yourself a whole new product.
It turns out that you can enter a Pet Battle while in stealth (rogue only) or shadowmeld and the action won't break you out of either state. Stealthing only works for rogues in this situation, though, since engaging in a battle will bring you out of cat form.
But rogues don't get to have all the fun. night elves can use shadowmeld in place of stealth, except you can't move or else you will break out of shadowmeld. If you happen to challenge a wild pet, but the area is uneven or your character needs to re-position itself before entering the battle, shadowmeld will break. So be sure you're in a safe and open area before trying this out.
This could potentially come in handy for players on PVP realms that wish to just battle in peace, or for situations where a highly sought after pet is up for grabs.
In heavily contested areas (on PVP servers) where everyone is frantically searching for those hard-to-find pets, it's easy to tell which players are currently engaged in a Pet Battle.
If the player is of the other faction, what's to stop you from attacking them, breaking them out of their battle, killing them, and then "taking" the pet they were originally up against (once it respawns)?
I actually had this happen to me recently while hunting for the elusive Scourge Whelpling. When I finally found one and started battle, I thought my luck had changed, but a rogue decided to shatter all hopes and dreams. Naturally, I was killed and upon returning to my body, both the rogue and whelpling were gone. Or were they?
Turns out the rogue had stealthed, engaged in battle, and sniped the pet that I had just tried to capture. How do I know this? Because I knew about the stealthing/shadowmelding trick, I stuck around for a bit. The walk back to my body didn't take long at all, and the rogue couldn't have defeated the whelpling in that small time frame.
In the end, the rogue came out of stealth right where the pet had originally spawned and flew away, just as I had thought. It was a frustrating day, indeed.
Now, if I had been shadowmelded prior to engaging in the battle, no one would have been the wiser since both the wild pet and I would have been hidden.
One thing that you need to keep in mind, though, is that if you have a companion out and you enter a battle, it won't be hidden using shadowmeld. Only the actual stealth ability will cloak your little friends. So if you plan on trying this out, don't give yourself away by having a pet out! :P
I don't know if this ability to have "stealthy Pet Battles" will be nerfed/removed, but I certainly hope it doesn't. This seems like a good tool to have in certain situations. It's also not as if this gives anyone a huge advantage, since the player under the effect of stealth or shadowmeld isn't invulnerable or unattackable, just harder to detect. It's still completely possible to break them out of their encounter if you know where to look for them.
I realize that it's probably unfair to non-rogues and night elves, which could be a viable reason for removing this. But... well, is there a but?
I guess the only reasons this would stay in-game is if developers feel that it's not a gamebreaker or that big of a deal since players can still be detected and attacked, or if there's no actual way to "fix" this so that you're taken out of stealth and shadowmeld when entering a battle.
Other than that, I have to admit that my desire for this stay the way it is, is completely selfish. :(
Is it wrong that sometimes I just want to battle without the fear of someone coming up and killing me and/or sniping the pet I tagged first? Ok, well the fear is still there, since anyone could walk right through me and realize, 'hey, there's this person here that I can kill!' Or if someone sees me walk up to a wild pet, disappear, they'd naturally get curious and walk over to investigate. But in a hidden mode, that paranoia is slightly reduced.
Sometimes I don't mind getting killed. Other times I do. Just knowing that I have the option to stealth-mode into a Pet Battle is a comfort, even if I don't use it as often as I could.
I can't use shadowmeld all that often for Pet Battles, anyway. There's a cooldown and sometimes it's just not efficient to take so much time to stop, shadowmeld, and then start a battle. In some situations, being slow to act will hurt your chances of capturing a certain pet.
Well, now that the cat's out of the bag, I guess I'll just have to wait and see what happens.