Currently, if you have a loot code, you redeem it and then "purchase" the mount from an NPC vendor. The mount immediately becomes soulbound. This two step process allows unscrupulous people to easily scam prospective mount buyers and subsequently hack their accounts. In patch 3.2, redeeming the code will automatically place the mount in your inventory, unsoulbound and available for legitimate in-game transactions.
Bornakk warns that if you have already redeemed a mount code, but have not purchased your mounts from the NPC, you will not be able to do so after 3.2. So it is important that you get your mounts before the patch is released, which could be as early as this Tuesday.
Patch 3.2 will bring about a new 5, 10, and 25 man instance to WoW, and usher in a new 40-man battleground called the Isle of Conquest. WoW.com will have you covered every step of the way, from extensive PTR coverage through the official live release. Check out WoW.com's Guide to Patch 3.2 for all the latest!