The University of New Mexico has announced that its law dean, David Herring, will step down after two years leading the school. Herring stated that "it wasn't a good fit for me to lead the school." More details here. The Provost took the unusual step of announcing that it will replace Herring with an internal dean this summer.
In this account, Herring made a claim I have heard repeated - that the median law school dean tenure is two years. I just don't think this is true - as this chart created by Jim Rosenblatt indicates. But it does seem to be true that law school deans are serving shorter and shorter terms.