In this paper a review of the pedagogical, technological, policy and research challenges and concepts underlying mobile learning is presented, followed by a brief description of categories of implementations. A model Mobile learning framework and dynamic criteria for mobile learning implementations are proposed, along with a case study of one site that is used to illustrate how the proposed model can be applied. Implementation challenges including pedagogical challenges, technological challenges, policy challenges, and research challenges are described. These align well with the themes of EduSummIT 2013 that hosted the dialogue resulting in this paper.