Good idea, but the particular visualization (moving shadow) is a bit annoying. I would go with something less in-your-face. Maybe a light shadow that blinks cou

Good idea, but the particular visualization (moving shadow) is a bit annoying. I would go with something less in-your-face. Maybe a light shadow that blinks couple of times on focus? I don't think the directional aspect of this is very important. Users just need to know where the focus is now, not where it came from.