Many believe it will be Robotics.* You might think we are still light years away from having personal R2-D2's running around the house cleaning up after the kids, but that reality is far closer than you think.
New video footage from the Ishikawa Komuro Laboratory demonstrates "skillful manipulation," or the ability to replicate complex motions, which demonstrates just how far robotic technology has come. Watch the robot catch a spinning cell phone in the air - it is impressive!
If we can manage to master the energy problem, ensuring a steady supply of clean, affordable electricity in the next 20 years we will have a new kind of boom on our hands, one which poses some serious social (and maybe even ethical) challenges.
When robots become smart and precise enough to produce the results shown above at manufacturing scale, one wonders how quickly us energy-hogging humans might start getting pink slips simply because our robotic counterparts are so much more energy-efficient and (needless to say) more productive -- no sick days, no personal phone calls, no Facebook distractions...
One wonders what that future would look like and what all those unemployed humans will do. Shop for robots?
*NOTE: There are actually two different theories about "the next industrial revolution." Some say it will be Robotics others say Nanotechnology. Some say a combination of the two.