One thing I'd love to see return to Disneyland or some part of the Disneyland Resort are the mermaids. If there is any place besides the lagoon over where Nemo's subs are then this The Little Mermaid ride would be the ideal place to have mermaids return to the park.
Whether it'd be in a large tank where a mermaid performs under water for the people waiting in line or they build some kind of water area where the performers can swim up into a watered portion of the front entrace area where the mermaids can talk and pose for pictures.
You could have ariel and all the sisters out there welcoming guests and doing whatever it is mermaids do.
So... good idea or bad idea.