Newer technologies, termed as Web 2.0 and Social Computing (SC) facilitate online social interactions. However, the broad impact of SC in diverse domains and the complexity of features that span diverse disciplines poses new multi disciplinary research challenges. Among these challenges, we are interested in a reference model for enterprise interactions that drives an architecture, which in its turn guides a deployment method for enterprise SC Applications (SCAs). Systematically integrating SCAs with Service-Oriented Architecture (SOA) and Web Services (WSs) will move enterprise architecture towards Enterprise 2.0; and propose an interaction reference model and an interaction architecture that guides a systematic realization of Enterprise 2.0.