Personally, if they make a fourth, I feel that they must bring him back. It would just be so inconsistent that Will and Elizabeth would go to the end of the world to bring Jack Sparrow---a man they barely knew and who had caused them more than enough grief by that point---back, then why wouldn't they do the same for a loyal friend whom Elizabeth had known almost her entire life and who had literally died for her sake?
As much as I don't like Elizabeth (and Will is kind of annoying, too), I think it would be out-of-character for her to not want to help James. I can only hope that ten years in purgatory (unless the fourth takes place before Will comes back from the Dutchman) enables him to get over her (vault over her, please!!) and they allow him to finally meet his proper lady-fair who will love him just as much in return.
Oh and did anyone see the James Norrington action figure? I don't have a picture, but if you loook at the back of the box for his little biography, they chose the worst picture ever for him! He has this "duh?" kind of expression, and its definately not heroic (even if it is cute, to me anyway).
I also have a little comm that I just founded, norrington_love in case anyone is intersted... (shameless promo) :)