Most ArcGIS Server applications are designed using many services at one time.
Each service is derived from an existing Map Document and therefore require individual creation.
I would like the capabilities to open and overlay many Map Documents inside one instance of ArcMap in order to update my Map Documents (future/existing AGS services) as my web app serves them up.
In short.. The ability to open, overlay & save many MXD’s in one single instance of ArcMap.