I'm glad you're looking forward to the Shades, as I wrote them for Heroes of Shadow. I'm anxious to see their final form, as well!
My favorite bit about the stars in D&D comes actually from MM3, in the Star Spawn entry, where the book asks "why do some stars hate the world?". That single sentence carried so much flavor and possibility!
As for the dead stars and the Shadowfell, this flavor text opens some great possibilities: imagine the PCs need to go to to the Shadowfell, or need to seek out the council of a long-deceased king. They must find an old captain willing to sail not by the stars, but by the empty spots in the heavens, until those spots are filled with the grayness of dead stars!
"Second void to the left, and straight on until the gray dawn".