Just made my not-frequently-as-I-should visit to Nick Carr's blog to find his current post of some interest. What's interesting, to me, is that this notion of segueing from the productive to the unproductive (in the digital era, of course) was first noted with GUI applications, word processing in particular. Studies (no cites off the top of my head) over the last three decades, from memory, have found ever more elaborate word processing software haven't led to some kind of productivity increase. Why spend neuron activity trying to solve hard problems and conceive appropriate text for the solutions when you can worry about which font and background color to use? Hmm?
And the reason is clear: attention is easily distracted by flashing bling. Has always been true; the digital world only makes the condition more stark. Just as in the original Dark Ages, the coming Dark Age will find intellect hidden in monasteries.