Hi Alison, do you mean for updates of programs, emails, pages, etc? There are a number of recommendations for logs of this information, but it doesn't exist at this point.
Lead Detail View has the Activity Log for that person
Campaigns have a Results log
Notifications is an error log
A
Anonymous
June 17, 2015
I, too, am looking for an audit log. A report that will tell me what has been change from an administrative perspective such as new fields, mappings, pages, login history, etc...