Robert Silverberg

I did not read all the stories, some because I haven't read anything by the authors. I will comment on the ones I did (or tried to) read.

King's story is well-written, it takes place after Roland has begun his search for the Tower but before the first book in the series; while entertaining, it reveals nothing new. Goodkind's piece fleshes out a bit of the prehistory of his world, though it's the same quality as the rest of his writing (take that as you will). I couldn't get into Le Guin's story, it may have been written far after the original trilogy and thus doesn't have the same kind of weight. Martin's piece is a little snippet of the history of Westeros, nothing profound but still enjoyable (unless I missed a significant name, which I might have). Feist's story is not too interesting and is not significant to Riftwar. Jordan's piece is about how Moraine gets Lan as her Warder, early on in her search for the Dragon Reborn. It has a goodly amount of backstory, mostly relating to the Aes Sedai.