We have been moving along getting people switched over to Revit MEP, but I would say there are still quite a few AutoCAD and AutoCAD MEP hold outs. As an extra motivator to switch to Revit, I am introducing the ribbon into our AutoCAD products. I had left them out in the past for change management reasons. Having to learn Revit and a new AutoCAD interface would have gained me more bad press than I needed. Now that things haved turned a corner of sorts, introducing the ribbon into AutoCAD may actually help induce a conversion to Revit MEP.
Or it could just blow up in my face. Oh, well. Having things blow up in my face was long ago written into my job description.