Have a 3rd view which simply shows the current workspace in a nice tree view. Selecting any file shows the history (log) of changes for that specific file in the bottom pane as a nice summary. Clicking on any of the commits in that bottom pane will expand it to show the diffs for that file. The bottom pane should also be able to be toggled between the history and blame view.
I guess this is similar to Github's main source view where you can click into a file then toggle between views related to that file.
