I can't tell you how many times I say to myself, "I wish I could track changes on a Map Document!". Please end the CopyOf_MyMap.mxd cycle, by adding some type of track changes option to a MXD or allow for a Map Document to be checked into a Code Repository/CVS like Team Foundation Server, TurtoiseCVS, etc. I do realize this is a serious change to the architecture of ArcGIS, but I think this is something that would get wide support. Maybe this could be supported by saving the map doc in the Geodatabase. I seem to recall discussion of this back at 9.0.
