The new and improved Super Adventure Box will include a "World 2" area with new stages and an end boss called the "Storm Wizard." You can also play Tribulation Mode for a challenge, and the update will offer new Super Weapon Set skins, and the weapons from King Toad and Storm Wizard. You can also craft your own mini Princess Miya.
The update will also add some non-Super-Adventure-Box related features. Specifically, it will let you craft ascended weapons, and Legendary weapons will be buffed. Magic Find will be removed from gear, and instead become an account-wide bonus.