SO excited they added this option. We love swimming (and diving!) with sharks. We went were just at Discovery Cove last month, but we're planning to return again in the fall specifically for this (thank you, pass member and/or FL resident rates).
Its all inclusive from a food and drink (mostly) and access to the main things. Lazy rivers, swimming with fish, swimming with rays, aviary. Really there is a lot of stuff to do, and other than the grand reef I wouldn't do any of them.
Main up charges are:
Swim with Dolphins (Not worth it in my opinion)
Grand Reef (Looks super cool, I've heard good and bad about it. Havent done it)
Swim with Sharks (New)
Feed the Rays (New)
Upgraded drinks (Higher class wine, craft beer instead of domestic, and specialty drinks)