Make your toon look awesome.

[LtCmdLore]

This doesn't go away with druid shapeshifting, so it's one of the only ways to make my kitty look different from the others. I checked with my brother and, as expected, enemies can't see it while you're stealthed.
I see no downside to this.

There's a SHOCKINGLY large number of people actually complaining about this on wowhead and the bug report forums. . . So expect it to get 'fixed' pretty quickly.

I guess people enjoy not looking unique and awesome. . . ?

I understand that it has already been fixed for new people turning in the quest, so if you want to keep the effect simply don't turn it in. (I need a bigger quest log for all these quests I can't turn in by the way.)
According to Zarhym blizz attempted to make it bound to 1k needs, and somehow failed? I hope it still works when I get home today. . . Hopefully they'll have their hands so full with fixing cataclysm bugs they'll forget about the magus for a while.

[Kardus]

Confirmed not working anymore, the rolling restarts fixed this. I went and abandoned and redid the quest, and the aura is only available in 1k needs.

[Clones]

yea no longer works booooo

[maximumjones]

Fixt.

No longer works, close thread.

[Meloku]

fixed. as soon as I ported to stormwind it was gone. nice find though.