Q: Are the Warcraft and World of Warcraft RPG books considered canon?
A: No. The RPG books were created to provide an engaging table-top role-playing experience, which sometimes required diverging from the established video game canon. Blizzard helped generate a great deal of the content within the RPG books, so there will be times when ideas from the RPG will make their way into the game and official lore, but you are much better off considering the RPG books non-canonical unless otherwise stated.
O_O ...... All those years of work....now considered non-canon?! Holy crap!
Pandaren, Half-Elves, Half-Orcs, Ley Walkers, Plagueshifters, Argent Dawn Templars, Bonecrushers, Runemasters...etc etc....
All of that is non-canon now? So wait... if the RPG isn't canon, then what about the TCG? If the TCG is canon, yet the RPG books aren't in the slightest, then I'm afraid the Warcraft universe just became more bland than you can possibly imagine.
This is a pretty mind boggling thing to stomach, considering wowpedia, wowwiki and even wikipedia has noted the RPG books as canon for years, and many, many articles have direct references from those books. Did Metzen himself actually say that the RPG books, every single shred of it, is 100% non-canon?
Last time I checked, he did dismiss Finall Goldensword as being non-canon...but certainly not *everything* in the books altogether.
Oh well, time to move on. Adios, RPG.