I have read somewhere on these boards in one of the numberous mug threads that if you are doing a split stay you may consider that as "length of stay" and use it at your new resort. I sure as heck am not going to buy a new one exactly the same as the last one, just because Disney has gone generic on them. I have two from every resort we have stayed at in the past 5 years. I also read that you can actually use it at other resorts during your stay, but I am not sure about this. It may not be allowed, but no one will stop you because they all look the same now. Must not be a big concern to Disney any more.
As far as Disney breaking even, losing money, I don't think it's possible. Unless someone would actually buy 12 or however many drinks per day at the resort, it's still unlikely because Disney gets the Coke products virtually free.