The event will take place at Mickey’s Star Trader and Merchant of Venus at the Magic Kingdom on November 16th from 7:30am to 9:00am.
Merchandise available will include: Let’s Celebrate Mickey Mouse! T-shirt, Mickey Mouse 90th Limited-Release Pin, 18-inch 90th Mickey Plush, Mickey Glow Bow Wand, Original Mickey & Minnie Mouse Plush Boxed Set, and the Mickey Mouse 90th Jumbo Passholder Pin. The 20% Passholder merchandise discount will apply!
Passholders will also get a chance to purchase the new Mickey and Minnie-themed doughnuts at a special price, plus visit with Disney characters.
There is no need to register for this event, but a valid Annual Pass and photo ID is required.
Other guests will be able to purchase the special merchandise when the Passholder event ends at 9:00am.
Source: Disney Parks Blog