Currently, this is not possible--this might be a good one for the Ideas section!
However, you can track usage of Tableau Server workbooks and views by creating a Custom Administrative View.
By connecting Tableau Desktop to the Tableau Server database, you can query such information as users, number of views, background tasks, etc. The following Knowledge Base article provides instructions on enabling access to the Tableau Server database and connecting to the database in Tableau Desktop.
Creating Custom Administrative Views: http://kb.tableausoftware.com/articles/knowledgebase/creating-custom-administrative-views
Hope this helps!
Great info Tracy! This is great to help in tracking adoption and usage patterns on a large corporate deployment.