Hi Jeff,
Regarding the movement of storage_area in cr_items to cr_revisions. I think the current design is ok. I did submit a patch for file storage (4.5) so it can safely move from one storage to another on a per item level. Having the movement on a per revision level may open some difficulties, say exporting the items. You then have to look up everytime on cr_revisions before serving the content. Although your suggestion does make it easy to serve stuff and not join anymore on cr_items.
Anyway in my opinion the current per item level of storage is good enough.
