SMI Sidebar for containers should show the current containers contents
In the tabs of containers (e.g. access, properties, publish), you can drill down to a container's contents from the sidebar. The current workflow to move to the access tab of a direct descendant (content or asset) from the access tab of a container is to click the contents tab, click one of the links for the direct descendant, then click to get the access tab for the descendent. The access tab is a special case, since you can't click directly to it from the contents or publish tabs of it's container. But still, the extra 2 clicks could be cut out.
Then again, if we're moving towards an ajax'd sidebar, this may be a moot point.