Yes, the DVC resorts do offer the resort mugs. We purchased the mugs when we stayed at both Old Key West and Boardwalk and we definately got our use out of them.
So do they change the color or design on the mugs? With the non-DVC places I'm preaty sure that people returning with mugs in hand isn't a problem. But with DVC members wouldn't people keep coming back to the same resorts with their old mugs?
I bought a Chip and Dale one at SSR last year and notice they are different this year.
One thing I noticed and am wondering if Disney found a way to limit the use of the mugs. We just returned from OKW and noticed the mugs now have Fall 2006 printed on them. One CM commented the new Spring 2007 will be in stock shortly. The mugs at SSR are the same.
If Disney is planning to enforce the rule they will be good for only a quarter of a year and the old ones can be turned away. Time will tell.
Most of the resorts offer a Refillable Mug for around $12.00 that entitles you to refill it as many times as you'd like during your stay. Refills are usually available in the Counter Service areas, Pool Bars and some Lounges.
Mugs purchased are only good for refills from the resort you purchased it at for that particular stay and can not be used again for future stays.
The resort mugs are pretty much the only thing I drink out of, especially at work. It helps bring some joy into the workday. My poor WL mugs is starting to lose the picture on the side from so much use.
We have a Mickey Mouse themed office, and on one wall have installed at the top inexpensive wooden racks with pegs on them (from Home Depot/Lowe's/Ikea). On them we have hanging all our souvenir mugs, 22 at the moment, including the ones you used to have to buy on Wonder and Magic on DCL to get refillable sodas. They make a wonderful three dimensional "border" in a Disney-themed room.