Since the mid-1990s, the interrelationship between ICT, the location of media consortia and their innovation processes have been essential features of agglomeration renewals. In many arenas, academic research as well as policy-orientated projects have focused on understanding the factors operating the re-organization of new media and their development in particular major cities and their agglomerations. Increasing numbers of case studies have investigated particularly remarkable media clusters (Achtenhagen and Picard, 2011; Davis et al., 2009; Picard, 2008 and 2010; Von Streit et al., 2010) which are used as either exemplary models of developments or starting to question traditional industrial and economic growth policies (Backlund and Sandberg, 2002; Bathelt and Boggs, 2003). In this chapter, we will not address the policy implications of media clusters. We rather want to bring some preliminary reflection on media clusters, the dynamic of knowledge and agglomeration. We think it is premature to develop planning policies on clusters when the main issue remains to identify properly the role of knowledge dynamics and its economic implication in both the constitution of media clusters and agglomeration economies (Cheshire and Malecki, 2004; Oinas, 2002). At this moment, it seems unclear to what extent we are able to draw the right lesson of the accumulations of cases on the innovative performance of media clusters. In other words, we think that there are still spaces to investigate conceptually and/or empirically appropriate analytical tools and knowledge bases on media clusters.