How do we know the rapture of the nerds is nigh upon us?
One clue is the state of "hard" science fiction. Not Star Trek stuff, but science fiction that tries to visit a real world 10 to 100 years from now (the masters, on occasion, make a stab far beyond that).
Someone writing this type of fiction wants it to be readable for at least 5-10 years. If they write in 2005 about the worldwide telescope's debut in 2015, then they're embarrassed when it debuts in 2008. Their work takes a hit, and might even seem silly.
Charlie Stross, one of the grandmasters, tells us how hard this game is getting after reading an Economist article about "High tech leapfrog". A World bank graph shows how quickly new technologies are disseminating around the world, in a fraction of the time it used to take.
...Here, in a nutshell, is why writing near-future SF has become so difficult. Say you want to set a story 30 years out, and as part of your world-building exercise you want to work out what technologies will be in widespread use by the time of the story. Back in 1900 to 1950 you could do so with a fair degree of accuracy; pick a couple of embryonic technologies and assume they'll be widespread (automobiles, aircraft, television): maybe throw in a couple of wildcards for good measure (wrist-watch telephones), and you're there. But today, that 30-year window is inaccessible. Even a 15-year horizon is pushing it. Something new could come along tomorrow and overrun the entire developed world before 2023.
Speed up this uptake curve a little bit by pushing it 20 years out, and you begin to see the outline of an onrushing singularity ... from the pages of The Economist.
(This post was prompted by the discovery that what I thought was a new and imaginative candidate for a not-here-today everywhere-by-2023 technology to stick in my next SF novel is, in fact, already here in concept form and will doubtless be around by 2013 and as unremarkable as wallpaper by 2023 ...)
This DeLong article on the Invention Transition is relevant; memes are propagating even faster than technologies -- indeed they probably enable the technologic dissemination.