Language as tectonic plates

I like how John McIntyre summed up the changing of language in this post on You Don't Say.

Like the tectonic plates in geological theory whose shifting and grinding explain volcanoes and earthquakes, the language we speak and write is moving beneath our feet, sometimes slowly, sometimes explosively. ... But since we cannot tell with any certainty where the language is going, it is left to us to exercise judgment, individually and collectively, about what constitutes clarity and precision. We resist when we judge it right to do so, and we surrender when it is prudent.

Just last week, I was saying the same thing, much less eloquently, in a discussion of blogging for copy editors. The benefit of online conversations that I cherish the most is seeing where other copy editors stand on some of these languages changes -- and becoming aware of arguments I'd have never thought of on my own.