These are all great answers, especially the discussions about the V-Rod and Revolution engines.
However, it doesn't address the question where HD is going to find a new generation of loyal buyers after we all pass on. Speaking only for myself, I never looked at another rider or person as "Motorcycle Brand Identified" I just see them as another rider and person. Whatever they ride, American, European, Japanese, Indian (The country) or even Chinese I make it a point to invite them along on rides, tours and even the CVO Get Togethers. And if an HD is in their future, that's great. If not, it really doesn't matter as long as they ride.
I guess overseas is a good option, Europe, South America and Asia might be able to help carry the MoCo until a new generation of loyal buyers is developed.