Diablo 3 - What We Know So Far @ Shacknews

Shacknews has a nicely constructed FAQ on Diablo 3, broken down into different categories.  Here's the general overview part:

• Largely follows in the style of past Diablo games.
• Controls and camera kept simple, but depth of combat enhanced.
• The story takes place 20 years after the events of Diablo II.
• Greater emphasis has been placed on a character-driven story.
• Targeting a length similar to Diablo II, which ran four acts.
• Uses a new in-house 3D engine and the Havok physics engine.
• Has been in development for four or five years. Was rebooted after Blizzard North shut down in March 2005.
• The game is "really far along," and is "really fun to play already." (Source: GameSpot)
• Dev team now up to 50-55 employees.
• Will ship simultaneously on Mac and PC.
• No plans for a console version.
• No decisions made on financial model.
• Blizzard challenged themselves to add color to the art style while maintaining the dark, gothic feel of the previous titles.

Looking at the last one, some fans have started a partition to express their disappointment on the artistic direction - an interesting counterpoint to the articles arguing Diablo 3 is a faithful sequel, while Fallout 3 has gone to the dogs.