3D Virtual Worlds are being used for education and training purposes in a cross-disciplinary way. However, its widespread adoption, particularly in formal learning contexts, is far from being a reality due a broad range of technological challenges. In this reflection paper, our main goal is to argue why and how identity federation should be discussed and adopted as a solution to several barriers that educators and institutions face when using Virtual Worlds. By presenting a clear set of scenarios within different dimensions of the educational process, as classroom management, content reuse, learning analytics, accessibility, and research, we consider identity, traceability, privacy, accountability, and interoperability as main concerns in order to support our argument. Finally, we conclude the paper by presenting paths to a proposal for a workable solution, through the analysis and reflection of different and current efforts that has been made by other teams, towards future technological developments.