Current developments in cybernetics, robotics and machine intelligence indicate that within the foreseeable future (and possibly the lifetime of the next generation) such devices will have a thinking capacity superior to that of humans. This will severely disrupt human society, especially if the management of global society is dependent on the ability of such computers to deal with its complexity.
If machines can be made as intelligent as humans, then the human race will effectively cease to be the dominant species. Machines will take over and destroy humanity or condemn it to a slave-type existence. People who believe that this will never happen are not being realistic.
What awaits is not oblivion but rather a future which is best described as post-biological or supernatural. It is a world in which the human race has been swept away by the tide of cultural change, usurped by its own artificial progeny.
Unleashed from the plodding pace of biological evolution, the artificial children of humanity will be free to grow to confront immense and fundamental changes in the larger universe. Humans will benefit for a time from their labours. But like natural children, such intelligences will seek their own fortunes as the their parents silently fade away.