Suggestions about How to Profit From Wow Patch 4.2 Items
One of the first things that feel the supply pinch in a new patch is enchanting mats. New gear gets enchanted, and now that there's a cheap and plentiful supply of Miscellaneous Mounts Maelstrom Crystals in the new 5-mans, people are starting to enchant their gear with the best-in-slot options. Enchanting mats are such a high-volume market that the prices are quite stable, unlikely to swing greatly from day to day. If you don't have the desire or ability to actually make mats, you can participate in the patch wow gold rush by buying them when they're cheap and holding them until the patch.
The second thing is Jewelcrafters, it also benefit on patch week. All the new gear coming into the market being enchanted is likely also being TCG Loot gemmed, and that means demand for cut and uncut gems will skyrocket. As with enchanting mats, you can either produce more in anticipation or buy some expecting to resell them.
If you can't cut gems, I'd stick to the obvious high sellers and avoid the niche cuts, even when they seem dirt cheap. If you can cut wow gems gems, just stock up on uncut, but do your best to get reds more than anything else.