I think that just having Title and Description would be plenty, and much easier to explain to people.
Having a wysiwyg description would be good - even if only so that people can put in links to other parts of the same site.
What would happen when you dropped the Caption and Story? On our site (/tewinvillage) we would want the current Title to be replaced by the Caption, and the Description and Story concatinated in the Description field.
If this could be done automatically it would be great, otherwise we would need some warning, so we (who am I kidding - I) could go through all the photos and fix the Titles and Descriptions manually.
