Putting aside the talk of other DS's potentially appearing (which is actually a cool idea) I wanted to bring up one issue that may already have been talked about.
There's no real reason the (main) DS in Return of the Jedi would even need to look like it's always looked.
Sure the standard half-finished look is iconic....but why can't it be something different and a bit more creative? It can still be something spherical but perhaps something more dark that looks hastily put together? Maybe something like this borg sphere. Anything like this would go a long way to helping distinguishing ROTJ from being a complete retread.
