Really fascinating move by Hyperion. I think it marks an intelligent strategic shift but one that wont work for everyone. It allows them to concentrate capital on core brands and remove the distraction of less essential brands that might well be better housed under other houses. It will be interesting to see how their rivals react. It certainly provides an alternative to merger mania which has been prompted by the Penguin/Random deal:
The decision means that Hyperion is migrating away from the traditional book-publishing model of actively competing with other publishers for new titles. Instead, Hyperion, which is part of Disney’s ABC Television Group, will look for books either linked to ABC television properties or that it believes can be extended to television or other corners of Walt Disney.
Eoin Purcell's Blog 
Focusing on core brands makes sense. But when does it become a case of all the eggs in one basket.