Taking the shine off "coruscate"

John McIntyre’s current word of the week is coruscating -- literally "flashing, sparkling, glittering," and metaphorically, per American Heritage, "exhibit[ing] sparkling virtuosity."

But do we have a consensus on that? I've had coruscating on my watch list for a while, and I think it may be shifting its sense in a way that the dictionaries haven't yet recognized, though they surely have active files on the case. 

The thing is, coruscating is supposed to be complimentary, but sometimes it's obvious the writer doesn't mean it that way. Instead, it's a negative,  apparently meaning "corrosive, harrowing, scathing, excoriating, castigating," or the like. For example:

The poem ... is a coruscating portrait of her father as a dead weight on her mother's psyche. (New York Times, Nov. 8, 2012,  in a review of a book called "brutal and sorrow-filled.")

In his concession speech, Romney showed he had heard the message. He called for renewed bipartisanship, an end to coruscating political divisions. But the Republican hard men still don't get it. (Guardian, Nov. 7, 2012)  

One of the peculiarities of modern conservatism is that the most coruscating examinations of its doctrines are often issued from dissidents within its own ranks. (NYT, March 2, 2012).

Entwistle's early lack of leadership and gravitas led to coruscating attacks from media commentators. (Independent, Oct. 29, 2012)  

And though coruscate is listed as an intransitive verb, a few writers have coined an adjectival coruscated, which might mean anything, but seems unlikely to mean "sparkling" here: 

He slathered the walls with coruscated layers of paint and clay. (Observer, Oct. 28, 2012)

You close ''Don Quixote'' and ''Tristram Shandy,'' ''Middlemarch'' and ''Augie March,'' and the cosmos takes on a coruscated import it rather lacked before. (NYT, Aug. 19, 2012)

I suspect, after poking around the newspaper archives, that the change is more advanced in the English press; they like to call critical official reports "coruscating," and you know they can't mean  sparkling. So what's going on in your linguistic neighborhood? Does coruscate still shine for you, or are the lights going dim?


Update 12/13/12: I see that Ruth Walker, whose language posts at the Christian Science Monitor are (sadly) not all that easy to find, wrote about coruscate last year, and mentioned the "corrosive" connection:

This writer [on a website of the University of Hull] goes on to say, however, that people often use the word to mean "very hostile" or "savage," and suggests that the word they are reaching for but not quite finding is excoriate … Corrosive may be another word writers have in mind when they use the nonsparkly coruscating.

She also sums up why it’s so easy to spread a new sense.

When a 50-cent adjective like coruscating appears in a sentence where it's not essential to meaning, readers are freer to draw their own inferences. In this case, the two meanings are very different, but in any given context, each is likely to be plausible. Readers then use the word themselves in the meaning they have inferred.

Sure, a dictionary would help -- but we don't learn most words from dictionaries, and until someone throws a warning flag, the person using the word has no reason to doubt his inference.  As Walker concludes: "This is how language changes. Alas." (I'm not sure if this one is going on my "Alas" list or not, but that's a personal decision.)