Fog Computing is a recent and compelling paradigm that proposes to run information-processing services at the edge of the network. While interesting standardization efforts are being currently pursued by many organizations, most of them focus on management and orchestration functions and primarily propose the adoption of programming models designed for Cloud applications in the Fog. Instead, Fog Computing applications would significantly benefit from innovative solutions that adopt an "acceptable lossiness" perspective and manage information processing and dissemination in a dynamic and integrated fashion. This paper presents an overview of the opportunities and challenges in Fog Computing application development, proposes an innovative holistic Software Defined Networking (SDN) approach based on an information-centric and value-based service model to support those applications, and presents an overview of the Holistic Analytics and Networking (HAN) SDN architecture that we are developing to realize this ambitious vision.