I've been hacking on WikiBench some more. The primary addition is the recent changes pad, which you can see in the screenshot. It is a separate addin that hooks into the WikipediaChangeStream addin to provide a list of changes to the user. Clicking a row in the list will display that diff in the browser, as expected.
The preferences dialog shows off the preferences pane provided by the WikipediaChangeStream addin for managing which Wikimedia projects to monitor changes from.
A lot is probably going to change between now and the public beta, but this is a pretty darn good start.