This should be a must in salesforce.com reporting. Vote up this Idea – https://success.salesforce.com/ideaView?id=08730000000Bq4qAAC
If you are doing a History report (Case History, Lead History, Opportunity History, etc…) you sometimes want to filter to only show data when an old value = XYZ or the new value = ABC. But currently you cannot filter by new value or old value. I don’t know why salesforce.com explicity does not allow this but they don’t.
So go vote for this Idea. It will allow for more advanced history reporting.