Does anyone know the progress of the book? Is RJ still writing or is he planning on waiting until his health stabilizes?

He is working when he is able. There is a rumor going around saying that he is about half way done. He did have some chapters completed before the release of KoD, so its possible.

As far as I know, though, the official word is that the book will become available late 2008...at least that's what I thought I read, hehe.

half way done?! That would be SWWWWWEEEEEEETTTT!!... if it's true.