Punctuation as rhetoric

The author of the upcoming book, "The Language Wars: A History of Proper English," sees an increasing tendency "to punctuate for rhetorical rather than grammatical effect":

How might punctuation now evolve? The dystopian view is that it will vanish. I find this conceivable, though not likely. But we can see harbingers of such change: editorial austerity with commas, the newsroom preference for the period over all other marks, and the taste for visual crispness.