I'm am positive that once you Welcome Celia or Roz you will see more quests (whoever is listed highest on the quest list). But until then you will be stuck. The storyline jumps around. I think you are in a Monsters, Inc. section. Once you finish that, then it might send you back to Toy Story tasks...or it might send you to Mickey & Friends tasks. The problem is, the game only tells you what unlocks that square, it doesn't tell you have to finish before you get to the point where you have tasks to unlock that square.
Are you familiar with the DMK Wiki? This page shows the squares that make up each land and what quest opens them.
http://disneymagickingdomswiki.wikia.com/wiki/Expand_the_Kingdom In Tomorrowland, there are only 4 squares that the Main Storyline unlocks. I'm not sure which ones you've already opened, other than clearing the Curse around Space Mountain. If you are trying to unlock any of the optional areas, those unlock, WAY, WAY later in the game. After you clear your way to the portal between Fantasyland and Tomorrowland, you will battle Zurg and that leads to the Fantasyland section. But you have to finish Welcoming the necessary characters first.
