Since no real objection has been voiced, I consider my proposal of having stable urls for all objects as accepted, but I want to raise the question of how to achieve this once again.
Can we go with having a service contract to figure out the local url to display an object that every package has to implement for every object type it provides? Would the name of AcsObject.Url be acceptable?
Should we have a global vuh-page as i suggested - possibly extended with optionally letting the user add a locale to further specify the object translation (not sure how to implement that one)? Advantage: we could have a really easy to remember mechanism like /o/$object_id. Or do we want to go the normal way of providing a global page like object-display?object_id=$object_id ?