I would find it hard for small outfits to truly learn all the ins and outs of a software like Revit. Especially since AutoDesk comes out with a new version every year and their are always compatibility issues between years. Even small architecture and engineering firms utilizing Revit typically employ a full time person to be their in house Revit expert. With that being said, Revit does play nice with AutoCad in that you can import AutoCad drawings and either use them as background layouts or they can be imported as 3D "families" (Revit language). Now an area where I think Revit would be incredibly useful would be for a furniture designer who maintains a catalog of stock models that may only have slight variations between actual builds. You could develop those variations into parameters of the model and simply updating those parameters with drop down menus or numerical input would automatically revise your plans. You could even produce a bill of materials right off of your plans.
Rob, you can also write routines in Revit. I've developed a few that place equipment in an architectural floor plan based off an excel listing of locations.