What happened to all the extremely interesting efforts like EROS (http://www.eros-os.org/) with its global persistence (i.e. can basically recover back to the previous state from switching off the system), Amoeba (http://en.wikipedia.org/wiki/Amoeba_distributed_operating_sy... multiple hosts seen as one) and others that actually brought extremely useful (even from today's perspective) new paradigms to the table?
Most new OS-related efforts seem to happen around virtualization nowdays.