Certain single shots (such as a shot to a Zuse target or Quorra spinner), but not all (Gem?) attempt to provide feedback. It's not rock solid yet, so sometimes it doesn't show a Quorra shot, etc.
For modes, it only displays the highest ranked active mode, so if you have Zuse and Clu running, they would be lit white, and you wouldn't know from just the ramps that Clu is also running.
Also, it gets pretty tricky to detect the start and end of these modes sometimes, so there are still some bugs, especially at the end of multiball modes.
Still, even with these things, it actually is helpful in letting you know what's going on, and it's only going to get better.