No amount of fluff will save the whole "my beard is a porcupine" issue at the heart of 4e duergar.
I guess the article's great if you need some more underdark devil-tinged raiders? I gots plenty (that don't have beard quills), thanks.
The whole beard quills thing is odd, but I assumed it was because they were creating a greater connection to "bearded devils", which have been around for quite some time and all that.
Ie, the whole duergar <-> durzagon <-> barbazu circle of "life".