We also don't know how many rooms are in the block. There's another con at McCormick Place that runs through Thursday. I'm sure they have some number of rooms at the Hyatt. We also know some people were savvy enough to book the Hyatt when the announcement was made. So while the Hyatt has 1,200 rooms, it's probably safe to say the number of rooms in the block is under 1,000. How much under that is hard to say. Edit: I looked and that other con has 75 hotels each available at the Hyatt and Marriott. Before you get any ideas, the dates for those blocks don't stretch throughout Celebration.