This article explores several professional development models currently being used in the US and in other countries to support teacher learning, including coaching, mentoring and communities of practice. While in some contexts the activities of the participants are informed by social constructivist views of learning, the authors argue that communities of practice offers the most promising lens for sustained growth and change. Two contrasting scenarios are presented offering a sharp illustration of the difference between a coach who assumes and maintains the position of expert, versus a consultant positioned as a collaborator and colleague in meaning-making through turn-taking and authentic dialogue. Literacy coaching and mentoring based on traditional definitions and practices may set the tone for professional development that diminishes the power and voice of teachers as agents for change--their own and that of their colleagues. This article emphasizes that it is the language of collaboration and dialogic processes that influence the development of learners within the community as it simultaneously shapes the identities of those who inquire within it.