Pre-order, Due for release on 23/11/2007.
Requires original "The Elder Scrolls IV Oblivion" to play.
If you already have Oblivion (like me) this is for you, no need to spend £40 on the GOTY Ed or download it from xbox live with no re-sale value!
Shivering Isles features more than 30 hours of new gameplay and allows you to explore an entirely new plane of Oblivion - the realm of Sheogorath, the Daedric Prince of Madness. Shivering Isles adds to the existing world of Oblivion so you can continue playing with your existing save game/character, or create an all new character just to explore the new content.