The Elder Scrolls III: Morrowind: Tribunal is a yet unnanounced expansion for Morrowind. We expect an official announcement in the first week of September. It will contain:
1) Mournhold, the anchient capital city of Morrowind.
2) clockwork city of Sotha Sil
3) epic sized dungeons (!)
4) goblins, liches, and other creatures
+plus plenty more.