We examine current mixed reality (MR) environments, looking at what they are, what can and cannot be done, and the challenges and possibilities looking forward. The contribution of Milgram and Kishino’s one-dimensional mixed reality model from 1994 is acknowledged with possibilities noted for extending the model to two- and three-dimensions. The challenges and possibilities for MR looking forward are summarized as seven community challenges (CCs) derived from current research and to be examined by MR researchers.