My friend Emily is at Comic-Con this weekend, so I'm taking care of her 12-year-old cat, Artemis. You can't see it in the photo, but he's standing on top of my fridge, apparently warding off intruders with his fierce squeak and his Left Eye of Sauron (no, it's not a lighting trick; he has heterochromia). A true catgoyle.
Why doesn't blizzard release a massive, canon, lore encyclopedia? The only thing that's close are the old RPG books that came out years ago and Blizzard themselves said those were non-canon and shouldn't be used for serious lore reference.
I feel that we're only able to learn small amounts of lore from off-hand comments in quest texts and the rare Cdev forum posts. And the books can only address the lore to a certain degree without deviating from the main story.
I'm not asking for a book that would spoil future story lines but instead something that would give context to the many cultures seen in the game.
What I'm imagining is a book that I could open up, look up the entry on Arakkoa and find a 2-3 page info on them, describing their customs, leaders, famous historical stories and what not.
It would be pretty difficult to create a work like what you're describing, due to the fluid nature of the WoW story. Blizzard creates lore to fit gameplay, not the other way around, so any info you get is bound to change or be added to at some point, any characters subject to Old God corruption or retcons. And when Blizzard does attempt to publish lore, you run into issues like the RPG books, where the information contained therein may not even be accurate anymore when a new patch or expansion lands, if it was ever really accurate at all. Hell, Blizzard couldn't even keep the game manual updated to say that no, you can't play a dwarf mage (well, you can now...).
As cool as a nice hardcover encyclopedia of WoW lore would be, I really doubt it'll ever happen. WoW's lore is just too malleable, too ongoing.