Add the ability in the app management area of the site to upload a config file that will configure/create your app. This would allow the ability to have your app’s configuration checked into code into some source control system that could then be monitored for changes. This would make it easier to track the subtle changes you have to make sometimes (endpoints, developer name/email, description updates, etc.)
On the other side it would be nice to have a history of changes to your app so if something is changed you would know who changed it, when, and what was changed.
These two things would be great and make the marketplace and app creation even better.