The Babylon 5 DVDs also did this, in the Season 5 boxed set -- JMS and some of the authors discussed the various novels and short stories, and how they were largely as canonical as the actual TV episodes. This was a good call on the DVD producers' part, and served to reinforce that universe's relationship with its tie-in product (although ST doesn't treat its offshoot fiction as canonical).
About the only thing they missed out on was the opportunity to include coupons or cross-promotional materials in the DVD sets advertising the existence of the novels before then, since the entire Del Rey run was still in print at that time.