You can see what type of data source a workbook is using by going into Data Connections (under Administration). Then, find the workbook and click on the data source to see more information. Hope this helps!
I'm not sure this answers my question. It seems like there is no way, simply by looking at the "All Workbooks" view, to tell which workbooks were published using an extract vs the workbooks that used a live connection.
Even viewing the Data Connection information only specifies the source of the data. Not whether an extract was created from that data source.
Thanks for your reply.