Not so long ago I joked about putting a Cray-1 in a watch.  Now that we are essentially living in the future, what audacious (but realistic) architectures can we imagine under our desks in 25 years?  Perhaps a mesh of ten-million of today's highest end CPU/GPU pairs bathing in a vast sea of non-volatile memory?  What new abstractions are needed in the OS to handle that?  Obviously many of the current command line tools would need rethinking (ps -ef for instance.)

Or does the idea of a single OS disintegrate into a fractal cloud of zero-cost VM's?  What would a meta-OS need to manage that?  Would we still recognize it as a Unix?