I've just switched to Tableau 10 and immediately noticed change in wrong direction related to layout editor.
In all previous versions deletion of container moved all object from that container up to the hierarchy level where deleted container previously was. Now it just deletes everything belonging to that container.
Cleaning up layout (after mess done by drag&drop) now is twice as annoying as before.
Please change it back to what it was (or give us an option to preserve contained objects) and while you are at it, allow us to drop new objects and move existing ones within layout tree.