This involves the use of [Tome of Polymorph:Turtle]; the vast majority of the wow population knows that ZG will cease to exist once cataclysm hits, so people are farming ZG as much as they can in attempts to get the mounts, tome, and razasshi raptor vanity pet. What very few people know is the Tome of Polymorph will still be accessable in cataclysm and not removed (like the pet and mounts).
A very easy way to capitolize on this is buying the tomes off the AH for around 200g (price they were on my server) and reselling them for 1000-1500g (price Im getting people to pay for them).
People beleive that the tomes will be gone so are willing to spend considerable amounts of gold to obtain an item to use or resell later in cata when it becomes rare.
For those of you that dont know, the tome of polymorph turtle can be farmed by completeing the quest
Nat's Measuring Tape - Quest - World of Warcraft Purchasing Mudskunk Lures, and fishing up 5 zulian mudskunks from ZG to summon the fish boss.
Side note: The lures and fish are NOT BoP so if you have more then one character that can solo the boss and only one fisher, mail him a few lures and fish and keep at it.