I have published a technical report that discusses the implementation of our vertex connection and merging algorithm:
Implementing Vertex Connection and Merging
http://www.iliyan.com/publications/ImplementingVCM
The focus is on the efficient path MIS evaluation. Special cases are discussed, such as correctly handling infinite lights and orthographic cameras, as well as point lights and specular materials. There's also a discussion on how to apply the weight scheme to bidirectional photon mapping and bidirectional path tracing. In the latter case, the scheme reduces to something almost equivalent to Dietger's. The slight differences are because the scheme was independently derived (but I obviously couldn't publish it before the VCM paper).
