From the cutting edge of innovations in online education comes the MOOC (Massive Open Online Course), a potentially disruptive and transformational mechanism for large-scale learning. What's the role of librarians in a MOOC? What can librarians learn from participating in a large-scale professional development opportunity delivered in an open environment to illuminate their own practice? This paper explores the experiences and perceptions of librarians and information professionals participating in an LIS-centered MOOC taught by the authors. We will share insights gained from active participants in the course as they encounter this emerging landscape.