A couple of clients have made note that they would like to have the ability to have a monthly option for the threshold of when content is determined to be obsolete. Possibly starting at 6 months since some content can tend to have a much quicker turnover.
Also, another client has suggested the ability for the content that shows as obsolete to easily be moved out of that filter, regardless if it's been used or edited. Some clients have content that the system may show as obsolete based on whatever threshold is set, but for the client they truly don't deem it as such and would prefer to have an additional option of "keep" or "move out of obsolete content" as well as the "delete" and "archive" options.
Also, if content in obsolete is without an owner and then an owner and review cycle is added, that content should move out of obsolete since a change/edit has technically been made.