Blizzard published more information about the upcoming new professions Jewelcrafting and Socketing. They also included a web based example of how it will work.
Jewelcrafters can learn several types of cuts for each kind of gem: the Azure Moonstone, for example, can be cut into a lustrous, stormy, solid, or sparkling Azure Moonstone, and each one of these cuts offers different bonuses when used in a socketable item.
Take a look here.