Whatever they bulldoze the Speedway for, TDO would do well to leave an opening for future expansion behind the Speedway and Space Mountain.
I'd rather see TRON go in the space behind Speedway/Space and see the Speedway used for either something like Discovery Bay or Wonderland/Neverland mini-lands (Pooh taking over the Tea Cups/Cheshire Café area, Neverland on the side closest to Storybook Circus, Wonderland closer to Tomorrowland with a fitting transition)