The T'au is the main focus of this weeks' pre-orders from Games Workshop. New Codex. New accessories. New model kits. But if you're a 40k player of any type, there's a pair of books for you as well, plus 2 Space Marine figures. But that's not all, there's the new edition of Spike! for Blood Bowl as well.
From the article:
After weeks of previews featuring everything from tactics to transports, the T’au Empire is finally ready to kick off a new Sphere of Expansion. They arrive just in time for the latest season of Warhammer 40,000, and there are also new updates for War Zone Nachmund, including new missions, lore, and Crusade rules.