Wishful thinking I know, but I would love to see Disney add their old concept of Geyser Mountain to this park. Stick it right next to the runaway mine cars and extend Grizzly Gulch. That land would give a one, two punch for thrills; kinda like Frontierland at WDW does with Splash and BTM right next to each other.
How hard/expensive would it really be for Disney to do, they already have the ride system and the concept from Disneyland and Disneyland Paris, slight reworks to fit into Grizzly Gulch doesn't seem like it would break the bank.