After upgrading to 0.8.0 (could have happened sooner) the window manager plugin only allows the actions: "Minimize", "Maximize", and "Close All". Previously there was a "Focus" action available for running programs. This is also mentioned on the plugin's Wiki page. This has been tested with a number of different applications, none of them offer this action.
All other features of the plugin seem to work as described still, such as "Tile Windows" and the "Current Application" object (again, with the exception of the "Focus" action).