Source: Official Diablo 3 Website
Diablo themed 4g USB hard-drive with the full Diablo 2 game loaded on it. The base looks like Diablo's skull and the USB card is a soulstone.
Behind the scenes DVD, 200+ page art book, soundtrack
Plus exclusive in-game items like a WoW pet, Starcraft 2 decals and portraits and Diablo 3 aesthetic items.
Bottle cloud and bottled smoke dye sounds awesome, plus a pimped out banner and official angel jr. wings. Sounds like my toons will be decked out nicely come release.Diablo III - Aesthetic Artifacts
Call forth glowing angel wings, unfurl an exclusive banner, and dye your armor sets with the Bottled Cloud or Bottled Smoke items.