After over two decades of relative architectural stability for
distributed memory parallel computers, the end of Dennard scaling and
the looming end of Moore's "law" is forcing major changes in computing
systems.  Can the community continue to use programming systems such
as MPI for extreme scale systems? Does the growing complexity of
compute nodes require new programming approaches? Can performance
portability be achieved? Are new I/O models required? This talk will
discuss some of the issues, with emphasis on internode and intranode
programming systems and the connections between them.