Some of the essays there are just thinly-disguised promo pieces for various D&D novels, yawn. However, they have some very interesting articles in the "Classics of Fantasy" series, discussions of important and influential books of the genre that talk not only about a given book or series, but what made that book or series special and important. Some of the books are familiar, and others are more obscure. Fascinating stuff!
A Wizard of Earthsea
The Dream-Quest of Unknown Kadath (jamesbarrett take notice!)
Fafhrd and the Gray Mouser
There's also an interesting series of articles for budding writers, called (appropriately enough) Write Now. Enjoy!