Recently posted on the Autodesk website is DWG TrueView. This is the FREE DWG Viewer that many others had mentioned in blogs and discussion groups. It was finally released.
It is a stripped down version of AutoCAD. It gives users the ability to open .DWG and .DXF files. Additionally, users can Zoom & Pan, switch between layouts and model space, turn Layers or Views on/off, Plot files, and Publish to DWF.
Owners of Composer had a similar viewer under a different name.
DWG TrueView is avialable for free download from the Autodesk website. Click on the title of this post to get there.