BioWare's Courtney Woods has just announced on the official forums that the game is now available for pre-load to anyone who has redeemed their pre-order code. Check out the Dev Tracker quote below, or visit the official site for the full announcement. Stephen Reid also clarified the announcement on Twitter, and notified the community that the Early Access section of the Preorder FAQ had changed.
In addition to moving the start of Early Access up to December 13th, the FAQ notes that there will be no "grace period" for preorder purchases; when Early Access ends (just before launch at 12:01 AM EST on 12/20), the servers will go down for a short time, and when they come back up all players will be required to enter a Product Registration Code in order to continue playing. Check out the FAQ for more details, and look for quotes from Stephen Reid after the jump.
UPDATE: You can now preload the game if you pre-ordered by visiting the SWTOR official website and following the instructions listed in this post.