> Moss 2010 have the "relationship" between moss list.
What has been added in SharePoint 2010 (it's no longer called MOSS) are two concepts that get us closer to modeling SQL-like relationships in SharePoint.
1. Relational Integrity. When you create a look-up between two lists you can now specify whether to restrict deletes that would orphan children or to cascade the deletes.
2. Projected Fields. When you do join two fields together, you can now promote fields (read only) from the parent list into the view of the child list.
The way that data is stored and accessed via the object model, however, hasn't changed. So if you have the need to create a join between, say, clients to projects to tasks and you want to report task information on the client, you're still out of luck
(without SLAM, that is).
We're in the process of working on the new version of SLAM which will support 2010. We don't have a release date yet since we're all pretty busy on client-projects.
Regarding your question about Hierarchy, not sure I understand...