Creating a new Workbench view showing recently updated content and its state
I think I figured this out, actually.


Create a new View which lists "Content revisions" (not just "Content"). "Save &amp; continue."
On the View edit screen, open up the "Advanced" right-hand column, remove the "Content revision: Content" relationship from the "Relationships." This causes the View to query the node_revision table, but join the node table in the vid field, which isn't what we want (because node.vid will not always point to the latest revision). Instead, add the "Content revision: Content: The revision NID of the content revision" relationship. Even though this one is also labeled "Content revision: Content," it'll join on node.nid instead of node.vid.
From the Filters section, remove the "Content: Published (Yes)" filter. Replace it with a "Workbench Moderation: Current" filter, set to Yes. Don't relate it to the new relationship we just made ("Do not use a relationship").
When adding entity fields, use the "Content (historical data)" ones instead of just the "Content" ones.


This approach seems to be working for my needs so far.

EDIT: In retrospect, I wasn't quite having the same problem as you were after all, since it doesn't sound like you were wanting to show only one revision per node. But I'll leave my answer up in case someone else eventually finds it useful.