Today I found some interesting information about Unity3.

There is a new PhysX version included. It supports layers and cloth animation among other new features. Here is a video of a destroyable cloth in action:
http://vimeo.com/12833414

And there will be a tree generator:




The new lightmapper can even handle hdr images. So you can light your scene via background image as an example. Or you can store the lightmap as HDR and do some professional post work.



The lightmapper is told to work with each shader available in Unity.

Here is some volumentric light effect:
http://vimeo.com/13012305

And they told that mod files (audio tracker files using very low memory) are supported in 3.0 as well:
http://blogs.unity3d.com/2010/06/29/mod-in-unity/

This sounds all very exciting to me.