Most of what I am going to talk about comes from the following site:
www.worldofwarcraft.com/info/professions
You can have two Primary Professions and any/all secondary professions.
Concerning the two Primary professions that someone chooses, there are some Primary professions that support other Primary professions... like Skinning/Leatherworking, Herbalism/Alchemy, Mining/Blacksmithing or Mining/Engineering.. etc...
Would the main reason to choose a Primary Profession with another Primary profession that supports it... be that you could actually gather your own items to synth? And if you choosed to not have a Supported Primary (ie: Alchemy/Skinning) you would have to buy your synthing items from other players?
Does having professions that support each other give any sort of bonuses OTHER than being able to gather your own items to synth?
Would having two primaries that dont support each other hinder you, or are there NPCs/stores (or maybe even other players) that sell the items needed to synth each craft?
Edited, Sun Nov 21 10:56:12 2004 by PentUpAnger