I believe, currently, there are two pin bag selections. Both are sold in the WoD, main collectibles room, along with the pins and binder.
1. Large, traditional pinbag, $38. About 10" x 14", zippered, handle, detachable shoulder strap, black, red piping, WDW logo. Inside, you have five thick felt-like pages that are actually pockets with velcro closures. Between each two pages you have a full size zippered mesh bag, and one extra mesh bag at the back. The inside of the back also has some pockets for a pen, paper, and other flat miscellaneous objects.
2. Backpack, medium, dark blue (?), not sure of price -- but it's less than the large pin bag. Has one or two outside convenient zippered pockets. Inside, three fold-out felt-type pages. Clear plastic dividers are between each two pages. I believe there is also one or two zippered nylng compartments at the front and back.