Drawing Exchange Format
Autodesk© DXF is not the very best file format for exchanging data between CAD softwares, but it is the only format that Autodesk have developed for it and is de facto the main one in the field of architecture.
The DWG format is a proprietary format and require licenses that are incompatible with the open source nature of Blender. So let's forget about it !
During the round table, there were some discussion around that topic : Remigiusz Fiedler - a Berliner architect and leader of the DXF import/export module - will soon give us some more details on the ongoings on this topic.