Hi,
I have a few fairly large complex applications that are currently using map services hosted on an inhouse ArcGis 10.1 server.  The CIO office would like to move toward ArcGis Online hosting.  Can a user publish a map to Arcgis online and have it be served as a map service (ie... so I can create DynamicMapServiceLayer),  rather than dealing with either a Web Map?   
I'm trying to get a handle on the scope of the modifications that will be needed. As a web Map is not quite the same as a Map made up of various DynamicServiceLayers on a basemap. 
I hope this makes sense.  
Thanks.