I'm unable to attach a workbook in a replay to "Server admin reports for workbooks, data connections, data sources, and their schedules" http://community.tableau.com/docs/DOC-5746 so starting new thread.
Hopefully this is of some use to server admins. Any improvements you can make would be appreciated. TZ is hardcoded to Pacific. Tested in 8.0, 8.1 and hopefully work in 8.2. You need access to the Postgres tables, not just the "tableau" views. See "readonly" in 8.2.5 or above or the grant approach for earlier versions.
The upper pane lists workbooks & datasources, whether they are schedulable(support extracts or not), when last they had a scheduled refresh, what the result was, when the next is etc, as well as the data source details & owner.
The lower pane lists details of the last 4 extract jobs corresponding to the selection in the upper pane. Useful for seeing details of recent failures. There's a Source Files tab too. The screenshot is a bit of a mockup.