Google Earth Extension for AutoCAD

"Using the simple wizard-driven interface, you can publish your 3D models from AutoCAD or select AutoCAD-based products directly into Google Earth™. The technology preview is available for 2007 and 2008 versions."

News are:

Added support for AutoCAD® Map 3D 2008.

Added support for map projections when using the extension with AutoCAD® Civil 3D 2008 or AutoCAD® Map 3D 2008.

Added tool tips for displaying time span data attached to AutoCAD entities.

AutoCAD® block references are now published without the need to explode them.

Download the free beta here.

Via Updated Google Earth Extension for AutoCAD available on Autodesk Labs

Wonder if and when there will be support for Virtual Earth 3D.