I think this debate has ended.
Has anyone ever been denied a refill?
It's simply a matter of Disney trading a week's worth of soda and coffee for thousands of dollars in park tickets, resort accomodations, food, and souvenirs. Disney will make that trade any day of the week and twice on Sunday! Any "dated mugs" are just to give us more fun in collecting and re-using them. The mugs are a PROMOTION and Disney is tickled pink when you bring them back.

Of course they do take up room in your luggage...
If nobody has ever been denied a refill, how did this this debate begin?

Sorry, I apologize for the confused "smiley" since I have also read a mug was good for only that visit at that resort. But I've come 180 degrees and I can appreciate the "enforcement" point of view. However, in my opinion such a "law-abiding" position just can not be maintained when nobody has ever been denied a refill in the history of the World. Regardless of signage or what appears on web sites, what matters is what actually happens in the food courts of WDW. (Whew, I hope this doesn't come across as epic or pompously profound

).
Maybe someone has been denied a refill...
But if not, I'd say use 'em and re-use 'em "until the end of time."
