For the similar reasons to what Kurzweil puts forth here: http://en.wikipedia.org/wiki/The_Singularity_Is_Near

Here it is in seven quick minutes: https://www.youtube.com/watch?v=1uIzS1uCOcE (Note: I think he's wrong in how he thinks it will unfold, but right in thinking the doubling every year of technology, in general, will contribute to bringing it about.)