August 27th is the expected release date of the next Disney-exclusive charms (aka not sold in Pandora stores).
Pictures can be seen at this link.
There are some charms that are expected to be sold in Disney parks, hotels, and other on-property stores and some that are exclusive to a specific location. Here are my guesses (I may be wrong about any or all of this).
Aulani - one new charm
Disney Cruise Line - two new charms
Disney Vacation Club - one charm (first DVC charm)
Epcot Food & Wine Festival - one charm, I would expect this to be sold at Epcot during F&W only
Parks/hotels/on-property stores:
2016 Edition
Fantasia 75th Anniversary
Minnie Holiday Wreath
Minnie's Sparkling Holiday Bow
Wishes Fireworks Show
And one non-exclusive charm also released on August 27th - Olaf (also sold in non-Disney-exclusive locations)