A few months ago, I wrote my guide to WoW PvE. At the time that I wrote that, Blizzard was tight-lipped in their design. Without their express design goals posted anywhere, everything had to be reverse-engineered from our experience in the game. In other words, my guide was a collection of guesses. I happen to think they're good guesses, but when you get right down to it, the amount of public data regarding those game design decisions I talk about was minimal.
All that's changed recently. Blizzard has a new and official voice speaking to the WoW class community, Ghostcrawler. I say the following with all due gravity: Ghostcrawler's posts are game design porn.