Charter schools have garnered strong support over the past decade, however, opponents question this choice option on many grounds, including their effectiveness, accountability, equity, and sustainability. This paper addresses these concerns by synthesizing what we know from the literature on charter schools, exposing areas where evidence is lacking, conflicting or ambiguous, and assessing the overall maturation of charter school reform. To help answer the question of sustainability, we draw in part on findings from our in-progress, long-term case study of a conversion charter school. This ethnographic data reveals the existence of serious challenges for researchers and policymakers, but also provides useful guidance for the future direction of the charter school movement.