PowerPoint doesn't provide any access to the Status Bar.
You might be able to provide the same functionality via a couple of controls on the Ribbon.
You'd need to install an event handler to trap selection changes, work out what slide you're on and whether it's changed (ie, does the ribbon need to be updated) then invalidate your ribbon controls so PPT re-creates them (with a callback into your add-in code to provide the needed font/layout information).
Personally, I'd find all that screen jiggly annoying; users might prefer to be able to click a button when they WANT that information rather than having it thrust in their faces all the time. And that would be FAR simpler to implement.