of what the future
It is a rather simple idea. At some point, a computer with the intelligence equal to the human mind will be created. Now, if you teach this computer how to design the next generation of a computer, it will do it in the time equal to a human. Currently, it takes about eighteen months to double the speed of a computer.
Now, once we double after this point, we teach the new computer how to design. As it works twice as fast, it will only take half the time to design the next one. And teach this new one, and it will only take one-quarter the time. And so on. Eventually, the speed at which each successive generation of computer is designed will reach a singularity - to visualize this, view the graph of the function 2x. As x increases, the curve grows faster and faster, almost reaching vertical. This may represent the speed of increase.
Of course, all this power could easily go into improving other technology also, causing technology to possibly change so fast that it is impossible to comprehend what things would be like.
Now whether this curve will keep accelerating, or eventually level off is unknown. But either way, it suggests a period of time where the very nature of life as it is experienced will change completely, with what lies on the other side being something that cannot be known until we're there.
And what makes this the most interesting, is the timeline given for this singularity, if it occurs, to happen. If the progression in various fields of technology are graphed, including various indicators of computing power and miniaturization, it appears to converge between 2015 - 2050, depending on the estimates used. The near future. Things might just be about to get wild.
See: Vernor Vinge on the Singularity for more details