Hi Lisa!
The Twilight Zone Tower of Terror Ten-Miler is a great race and really fun weekend! You're going to have a blast:)
I am so excited for the new wrist bands! I can't wait to see all of the new changes and possibilities that Disney will offer with the new system.
As of now, they have only been using the wrist bands on a very limited basis to test them. There is no official date for them to be introduced as the replacement for cards. It could be before Tower of Terror, but maybe not. Right now, no one can say that tickets will be given in that format, because the date just isn't set in stone yet. So, there is a possibility that it will be a wrist band, but I really don't think it will happen that quickly. As you can imagine, changing something over such a huge area takes a lot of time and testing. Be sure to follow along with the
Disney Parks Blog. They will probably post something before it becomes the official new "key".
I hope this helps! Please let me know if you have any other questions.