FastPass+ experiences will be selected from two groups of attractions, with one selection from the group 1 and two selections from group 2. The groups are currently setup as follows:
Group 1 (One selection can be made)
Group 2 (Two selections can be made)
As you can see from the groups, this means it will not be possible to hold a FastPass+ for both Toy Story Mania and Rock n RollerCoaster. The only option will be to use the standby line for one of these attractions. Those of you who already have FastPass+ setup will not be required to move into this test grouping unless you modify all of your existing selections.
A similar system will be tested at Epcot. The Magic Kingdom and Disney's Animal Kingdom are not yet using any attraction groupings.