Here's how to print money, alongside Energon, if they decide to retheme the restaurant:
A dark, oil-looking drink. Make it chocolate, chocolate-mocha (little bit of jamocha in the parks can't be a bad thing), or just mocha flavored. I'm sure they can figure out some way to put a spin on it to make it even more amazing. But, yeah, I gotta admit I'd be pretty psyched to try some 'energon'. One of the craziest things I loved about Potterland was the unique beverages. They have another chance to knock it out of the ballpark and build another money printing building next to the one they have behind MIB.
Just for the record here, I love the heck out of the current themeing.