ABC’s “Good Morning America” is detailing its plans for guest hosts while Robin Roberts undergoes treatment for MDS. We have already noted some of the people who will be filling in for Roberts, but today the AP has the scoop on some new names. Among the guest hosts: Comedy Central’s Stephen Colbert.

The guest-hosts will primarily be filling in during the lighter second hour of the program, though some with newsier chops may appear for the entire program. In a textbook example of corporate synergy, the cast of “Modern Family” will fill-in for a whole week, with a different cast member appearing each day.

While the idea of celebrity guest hosts has been tried before in morning television, ABC’s rivals at the ‘‘Today’’ most recently showed its potency when Sarah Palin guested and got strong ratings one day last spring.

With their experience in news, Walters, Sawyer and Couric will work for the full two hours when they come on ‘‘Good Morning America’’ for a day. Each has had extensive morning experience: Walters and Couric on ‘‘Today’’ and Sawyer on ‘‘GMA’’ and a CBS morning show.