According to the press release:
WorldCat Discovery changes will help users more easily get the resources they identify in search results. Records now display library ownership and availability information together, so searchers can more quickly determine how to obtain needed items. Links to materials available electronically appear first, so users can conveniently connect directly with available online resources. For items not available online, users can view a list of libraries that own an item, with the closest libraries appearing first.
For an in-depth look at the changes, go here.