A couple week ago, during the last debconf (Debian Conference) in Managua/Nicaragua, I presented the latest developments about the inclusion of clang in the Debian architecture.
To sum up (details are available in the slides and the video), the rebuild of the Debian archive with Clang 3.1 increased the number of failures from 8.8 to 12.1%. The main reason is that further checks have been added to clang.
With Paul Tagliamonte as co-mentor and Alexander Pashaliyski as a GSoC student, we made great progress in bringing Clang as A new compiler in the Debian infrastructure.
The various feedbacks that I had during Debconf were pretty good. It interests many people for reasons like Quality Assurance (more checks), performances, hackability or to decorrelate Debian and GCC.
Build Debian with another compiler - Slides
Build Debian with another compiler - Video
A nice resume of my talk has been made by Michael Larabel on Phoronix:
Decoupling GCC From Debian By Using LLVM/Clang