From what I understand, Esri has no plan to reintroduce the cartographic representation. After banging my head on my keyboard for several weeks to try and address how I was going to port my symbology, I've identified a few potential workarounds:
Option 1, Multiple Feature Classes: Create multiple feature classes for each scale that you need to symbolize. This is obviously very cumbersome, because it now means you have to maintain those feature classes independently. One idea to assist there is to create a composite relationship class between them to help cross the gap when editing your data.
Option 2, Annotations: Use something like glyphter.com to convert svg symbols to fonts, then convert your symbols to feature-linked annotation. You will need to use the original layer to generate symbols in the legend, but that's not much of a hurdle. Nice advantage here is that you can use leader lines to connect your symbols to their true locations.
Option 3, Offset Fields: Define your point offsets in two fields Offset_X and Offset_Y, then make sure the "Allow Symbol Property Connections" box is checked in the Symbology dialog box. Then you will need to edit your records in the table to place things as needed; no editing the offset placement directly. A quirk at the moment is that the offsets actually affect the positions of symbols in your legend, but you can work around this by adding another non-offset (and not visible) layer to your table of contents.
Esri, symbol offsets by geographic distance would probably be very helpful to some. Also, a tool to make edits to your Offset fields would go a long way to replace Cartographic Representation functionality.
Hope that helps!
Seth
