In the last several years there has been a noticeable focus shift of agile methods from eXtreme Programming (XP) and Scrum to Lean approaches, which is indicated as “from agile to lean”. However our understanding of the driving factors behind this focus shift is very limited. The study proposed in this paper attempts to investigate the shift through a content analysis of two major agile mailing lists. The expected result is a set of driving factors behind the shift from agile to lean, which can contribute to a better understanding of if and why Lean software development is “the next wave of software process”.