Blizzard released the first look at vendor pricing for gems when Mists of Pandaria Arrive:
|Gem Quality||Old Price||New Price|
|Rare (Perfect Cut)||9||1 10|
|Rare (Uncut)||3 20||3 50|
|Meta (Cut)||3 75||4|
(Courtesy of mmo-champion)
So why is it important to know this from the start? Because every expansion since Burning Crusade introduced Jewelcrafting as a profession had it's own version of a prospecting shuffle. Whether it was crafting simple rings to sell to the vendor for a quick profit to crafting/disenchanting items. The spreadsheets were showing mass amounts of profit from spending time performing what quickly became a Jewelcrafting ritual.
We do know what the Mists of Pandaria Version of the Jewelcrafting shuffle will be. But getting glimpses into the future with the vendor pricing shows that it probably won't be involving crafting/vendoring blank gems themselves.
Setting up our professions to maximize profit with minimal effort is going to be at the forefront of our responsibilities in the next few months. And even the smallest of information can give answers on what the future will bring with each profession.
Currently I'm holding onto stacks of gems that are going to be used for the jewelcrafting dailies. These are going to have higher and higher pricing the more rare they become. Most Jewelcrafters will work with Mists of Pandaria ore, and not be as concerned about production of previous minerals. This opens up an opportunity to those that have kept previous stock available. Zephyrite and the other gems that are used for turn ins for cataclysm daily profession quests will end up having a higher price tag on the AH. The same occurred withe gems from the wrath expansion. At the end of the expansion huge citrines were going for less than a gold a piece. Now they hold a premium on many servers 5 times as much.
The more information that is revealed, the more planning that can be done for profiting with the new expansion. So keep on top of all your information providers and make your plans accordingly.
Good Luck and Good Hunting