I'm sure I've said it a few times since I've joined the WoW Insider team, but if you're a Shadow Priest and don't stop in at ShadowPriest.com once in awhile, you're doing yourself a disservice. Even the bleedingest of bleeding edge players have room for improvement and can learn new things once in awhile. ShadowPriest.com goes well alongside Elitist Jerks for all of your gear, strategy and theorycrafting needs. Especially with all of the discussion that will inevitably crop up when the Wrath Beta rolls around, you definitely owe it to yourself to take a look.
[ Thanks, Matt! ]