This has been going on for a long while, I suppose, but I am moved to concern by the recent devolution of awesome to the status of a mere affirmative.
ME: "I'll have an americano and a biscotti."
KID: "Awesome. Chocolate or pecan on the biscotti?"
This kid will save up his tips, perhaps, and take a vacation to the Grand Canyon, where he will stand on the edge gazing into the vastness. I doubt he will say, "My God, this is ... this is . . . just like serving a guy a coffee-and-biscotti!" The appropriate word, which is awesome, has been lost for its original purpose. Now you have to say awe-inspiring, or something clumsier.
In fact, we have surrendered a host of useful words for extreme states because of our penchant for hyperbolization. If that party you went to last night was horrible, what was Treblinka? The movie was terrible. You mean it was like an army with banners? Yes, we have terrifying, but it's still a net loss of a useful word, as is awful. Awful and awesome mean the same thing etymologically, but one is bad and the other good, if in a vague way.
An example of this is the word modern, an extremely useful word of varying meaning, a spongy sort of word. But when it was introduced in the early modern (!) period it meant a way of dressing stylishly, but above one's station. If you called someone a modern fellow in Shakespeare's time, that's what you meant. Some process changed the word's meaning to the modern one and we no longer have a single word in English for that useful descriptor.
So is there a trend here, some tendency for language to drift away from the specific toward the vague? Or along with this devolution has there been an evolution of words created or pressed into service to describe states that are literally awesome, terrible, horrible, marvelous and all the rest? I don't mind language changing as it always has: words dropping into and out of currency and the invention of new ones. What I do object to is words disappearing without replacement. When a word loses its meaning in that situation, we can't easily express what it used to mean without going through some verbal loop, maybe a scatter of words, maybe a quasi-synonym, both of which tend to blur and weaken expression. Think about gay, as in "our hearts were young and gay." Or Nietzsche's "The Gay Science." Now it has become subsumed by what was once slang denoting homosexual, and these other useful and irreplaceable meanings are nearly impossible to use. Most people can make a list of similar lost meanings.
Gene Wolfe has a marvelous passage in one of his New Earth novels in which a character named "Loyal to the Group of 17" tells a story using only the degraded political discourse of a hyper-Maoist totalitarian state, which is all the language he has available. It's a tour de force, and powerfully affecting--he's telling a love story without any words that mean love. It seems horribly prophetic now.