Design visualization using Revit Architecture models with 3ds Max has become easier. Revit Architecture 2009 now features the mental ray rendering engine, which brings the product more in line with AutoCAD and AutoCAD Architecture, which have used mental ray for the past couple of versions.
The mental ray rendering engine in Revit will allow export through the FBX file format. FBX is an open-standard, platform-independent 3D file format that will allow Revit lights, materials and cameras to be imported into 3ds Max 2009. FBX also allows interoperability between 3ds Max, Maya and MotionBuilder.
For information on the FBX file format, check out http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=8224901