Much like the newer added support for adding Shp, CSV, GPX, etc. to ArcGIS online web maps, I strongly believe geo-referenced imagery needs to be supported as a new "Add Layer from File" supported format. Even if this was geo-jpg support only, this would be great. Other formats could be jpeg 2000 and GeoTiffs and if there is a file size limit that would be fine too. The uses of this would be huge for the smartphone applications in the field.