I'm an avid rare-pet-hunter, but I'm also an avid programmer, and this new 'appearance glitch' method has got me thinking about how exactly Blizzard CAN fix something like this

1. The inevitable hotfix
To prevent people from using the new 'easy tame', they can always break the macro. That part's not too terribly difficult.
But how to stop people from using the old method, the kill-as-you tame? It would require quite a bit of reworking on Blizzard's part to do the 'cleanse buff' method before the tame finishes. Not impossible, but a bit of an overhaul of the mechanic.
2. Dealing with the tamed pets
Oh, will Blizzard ban me for my pretty harmless pet?
No. Blizzard wants your money. It's extremely unlikely.
Oh, will Blizzard ban me for my pretty damage-buffed pet?
They should. But I don't know.
Do our shiny pets pose much of a threat to the WoW community? Even if they're on fire and have daggers through their heads? PETA might come after us, but not as such, no. I pondered about the possibility of Blizzard not even bothering to fix this until the 'damage buff' pets came into play. Houston, we have a problem.
Some lesser hunters have gone out and grabbed these buffed beasties, and they just about ruined the whole ride. Blizzard has to fix this, they have to wipe these pets, and I'm fairly certain out harmless ones will get caught in the crossfire.
3. To wipe or not to wipe?
The only instance I'm aware of concerning Blizzard tampering with hunter pets comes from my long-lost friend Garwal. Once a Worgen, he was replaced by a white worg model. Initially we thought they had removed the hidden buff, but instead, Blizzard did something else; they replaced his entire code with another mob, a Winterskin Worg. But why? To avoid later problems!
So, how do they deal with the 15+ buffed pets we've gotten out hands on? Going in one by one and replacing code with another mob? Unlikely. Blizzard probably won't risk trying to nab them all one by one. There's probably a few more buffed pets that haven't been posted, that cautious hunters keep to themselves. So that way's out.
Most people speculate on an arena-type wipe of pets, clearing all the buffs upon login and/or stabling. Likely. Extremely. Yet, a maliciously easy bit of code to get wrong. It'll be tricky on Blizzard's part to program something that does not affect players, but a minion, a side-player if you will. Imagine the storm if you get dced in a raid, and suddenly that expensive flask you bought is gone from your buff-bar because of your pet. Ugly.
Blizzard could do it, I'm certain. How long it'll take and how it'll be done is certainly still up in the air. We're sort of jerks for figuring this bit out right before Cata hits anyway

But I'm curious, Petopians. How do you think it'll be handled?