Check out the progress on the Tron Lightcycle Power Run attraction in Magic Kingdom!! You can see the track looks just about complete and work is continuing on the building around the indoor part of the ride.
There is a test vehicle as well, located just outside Space Mountain in Tomorrowland. It's like a motorcycle. You lean forward and grasp the handles which pulls the back up and over you, securing you into the ride vehicle. Lots of people were testing it on my recent visit.
We don't have a firm opening date for Tron, but expect it to open for the 50th Anniversary, which is in 2021.
Mary Graham is a Vacation Specialist with Coasters & Castles Travel. She has experience with Walt Disney World, Disneyland, Disney Cruise Line, Adventures by Disney, Universal Orlando plus Royal Caribbean and Norwegian Cruise Lines and Sandals and Beaches Resorts. Contact her at firstname.lastname@example.org