There is now a pre-release beta for a new Autodesk Batch Drawing Converter. The only difference from the existing Batch DWG Converter at http://www.autodesk.com/migrationtools is this version does not require any AutoCAD to be on the machine it is installed on. So now you can install on a machine with no AutoCAD on it and convert DWG files back and forth between R14 and the current versions of DWG used by AutoCAD 2006 using a native Autodesk tool.
To get involved with shaping the future of AutoCAD as well as testing this Stand Alone Batch DWG Converter or a upcoming AutoCAD 2006 Service Pack sign up at http://myfeedback.autodesk.com/.
Cheers,
Shaan