Have you seen other examples of guilds and peer review systems in other software?

My ideas for this largely stem from my work over the past twelve years with the Sudbury model of education, as per http://en.wikipedia.org/wiki/Sudbury_model -- the general way most of those schools graduate students is with a committee made of peers who help a student prepare a thesis, which is then defended at a school-wide meeting, where all school members (students and staff) vote on whether to graduate the student. This system has worked for over 40 years at dozens of schools around the world.

Additionally, the idea for using a Guild for this stems from the original medieval European universities of the twelfth century, which were grassroots guilds of students who pooled together their resources to hire teachers. That system was directly challenged by a system of state & church sponsored guilds of teachers who pooled their sponsor's resources to recruit students. We all know who won that particular battle, but the fight is not yet over...