In 2008 the National Leadership Computing Facility at Oak Ridge National Laboratory will have a petaflop system in place. This system will have tens of thousands of processors and petabytes of memory. This capability system will focus on application problems that are so hard that they require weeks on the full system to achieve breakthrough science in nanotechnology, medicine, and energy. With long running jobs on such huge computing systems the question arises: Are the computers and applications getting too big for MPI? This talk will address several reasons why the answer to this question may be yes
