What about a wicked cool show in tomorrowland or at the nemo subs at night that would pull a lot of people away from the parades and Fantasmic? I have no clue what it would be, but the crowds would significantly even out if there was an E-Ticket show over at the other end of the park...and at the same time as other shows as to avoid a giant moving mass from show to show. Between Fantasmic, Parades, and Fireworks, the crowds are all at Main Street, Adventure Land, NOS. Something at the other end would even things out.
Either that or they could have character fights at Big Thunder Ranch (under utilized space) where Mickey and Friends could duke it out...UFC style!!!