The Tower of Terror 10K Weekend is officially on sale today, February 5th, for DVC (Disney Vacation Club) and AP (Annual Passholders). DVC doesn't stand for Disney Visa Card, though sometimes in the past they've offered early registration, I haven't seen that yet for 2014 races. They do sometimes offer discount codes. Google "Disney Visa Run Discount Code" to see if anything comes up - it doesn't hurt to try.
I just completed my registration and I'm all signed up for the 5K and 10-miler.
With the way some of these races have been selling out (I've even seen a non-Disney, non-Boston/Chicago, etc., race go in 45 minutes!), I'd get to registering early if you're able to.
The AP links are as follows (please note, you'll have to sign in to the website and have your annual pass information stored before the direct links to access registration will become available:
I'm sorry that I don't have a link for DVC, but I'm not a member (yet!).
See you in October if you'll be there!