Grid computing.  Supposed to be the next big thing.  I'm sure it will, although
possibly not in the same explosive fashion that the internet was.  The internet
was a brand new thing - a whole new paradigm in communication and connectivity.
 Grid computing is essentially a new means of using the existing 'net
infrastructure.  An evolution rather than a revolution.
The forerunners of the grid are already starting to appear.  The SETI-at-home
project, P2P file-sharing etc.  Its not too great a leap from sharing MP3s and
parcelling out pieces of the sky for signal analysis to active collaboration of
distributed nodes to solve complex problems or provide services.
There are a few projects working in this area, the ones I can remember off the
top of my head being:
The JTrix project.
Gaia from The Mind
Electric.
[Insert obligatory cyberspace/the matrix homily here].