I agree with the CEO of Dunkin Donuts when he says that "beverages are the holy grail of profitability." For most people, a trip to Dunkin Donuts means picking up their morning coffee or tea. We, as consumers, can see the shift in Dunkin Donuts marketing to that of beverages just in their "America Runs on Dunkins" commercials. These are focused on beverages rather than on donuts. Although Dunkin Donuts is switching their marketing focus to beverages, I believe Doughnut eaters will still look towards Dunkins to get their doughnuts (at least in New England). The company is automatically advertising doughnuts just in their name.
New Englanders look to Dunkin Donuts for not only their coffee but for many of their breakfast needs on their commute to work. There aren't many other well-known doughnut shops in the region and where customers are already loyal to Dunkins and their coffee I don't believe that Dunkins needs to advertise their doughnuts to bring in customers. They will come no matter what, considering the reputation and legacy of Dunkin Donuts in New England.
I think that the only effect that not marketing doughnuts anymore will have on Dunkins is that they will actually be more profitable. They will be able to spend more money advertising their coffee, sandwiches, and new products that will bring customers in, and those customers may end up buying doughnuts anyways.