That's the Butterfly Garden, Reichart, and we already know it's going to be some time before that arrives!
It would be nice to have a shaded background in the Open Water tank - lighter toward the top, darker toward the bottom, possibly with sliders for each in the settings panel to control how light/dark each gets.
It would be nice to have the occasional skate or camouflaged ray move across the sand in the fantasy tank - and stop.
Debris, such as in the Goldfish Aquarium would be really nice, maybe moving in slight currents.
Plumes of disturbed sand following the low swimming Angel Sharks and the ray/skate above when it 'takes off' and 'lands' again.
If the colouring of the ocean tank background and lighting is set to be really dark then it might be nice to have some luminous fish turn up from time to time, but I know we're getting toward fantasy here. Still, as you guys said - it is a wish-list.