I think the world is changing rapidly, mostly in response to technology, but in ways that are unexpected.
As a writer and editor, I primarily think about the way communication, reading, and writing have changed. And while the various ways that we communicate have changed drastically (the "how" of communication), why we communicate has evolved, too. We check in, keeps tabs, send updates, and announce our states of being through text messages, Facebook, Twitter, IM, and so on.
I think the same can be said for how we communicate recipes. It's funny to me to watch the pendulum of trends swing. Years ago, there were no standards of weights and measures, so recipes would literally call for a "teacup" or a "spoonful" or a "good pinch." But once standardization happened, recipe writers and editors became obsessed with precision, noting not just how much of this or that to add, and what temperature to achieve, but also the exact dimensions of the pan, how to save leftovers and for how long, and with what to serve the food. If you think about it, that's really overboard, though I'm sure many of us have become used to it to the point that we expect those details to be given.
Now, with new forms of shorthand and new levels of informality taking over (what's more informal than getting "poked" by your uncle on Facebook?), recipe writers are testing the waters for how loose and free-wheeling they can be, too. Narrative cookbooks are just starting to regain popularity -- didn't Jacqes Pepin write a narrative cook book not long ago?
On blogs, I've noticed people often share recipes for different reasons today than they might have in the past. Bloggers will write about a personal emotional experience or memory to set up a recipe, rather than share a recipe simply because they think it's really tasty.
As multi-taskers, we digest written recipes differently now, too (I'm even writing this post while listening in on a non-critical webinar).
I've been editing a cook book that's in development and have been pleasantly surprised to see how different people respond to imprecise recipes. I asked some friends to help me try out the untested recipes before they're edited. So far, one person was abhorred, one gave me feedback that was full of short-hand suggestions, another went into deep detail about exactly everything that happened and everything that needed adjustment.
What will be interesting, from a publishing perspective, is whether printed cook books will be differentiated or whether they will go across the range from informal to formal, as is happening on the web.