There isn’t any new information, so I won’t call this an update. But, there is probably some information you have not seen.
Geenz Spad, a developer of the Materials System, has a web site with information about the Materials System. See: Geenzo.com. The article outlines the process that started in February 2012 and went public about July or August 2012. It is worth reading if you have something you wanted added to the viewer or Second Life™ or have any other proposal for Linden Lab to consider.
In the article the features environment intensity and specular exponent are mentioned. We hear little about these in most discussions. Without the features in the viewer to demonstrate them it is harder to explain them. I’ve linked to a couple of page I hope will help.
I’ve mentioned that Maestro Linden spoke of the server side of the project being in testing on ADITI. There once was a code repository where people could pull and compile a viewer with the latest viewer side version of the project. That seems to have disappeared from public view.
We have no ETA on when the project will go into open Beta, meaning when we get a project viewer.