It's worth noting that "processed" is a very loosely-defined term when it comes to food. At it's broadest, even peeling a banana could count as processing.

Check out http://en.wikipedia.org/wiki/Beef_aging

If you're eating aged beef, you're going to know about it, because it's going to be $30/pound... and this is hardly the sort of processing people should be concerned about.

I thought all beef was aged. I have heard the taste is unpalatable at best if it's not aged at all. I'm really curious.

I looked into this a year ago. You're right: "dry-aged beef" is the fancy expensive stuff your yuppie butcher is selling you. "Wet-aged" is everything else -- they pretty much stick it in a plastic bag in a brine that breaks down tissue. If you don't do anything what you have is a curiously tough meat product.

Wet aging is cheaper because you raise the water content (and thus the weight) a little, whereas in dry aging you lose a bunch of moisture, and because it only takes a week or so.