Let's hope Apple makes the lights brighter in a software update.
Don't count on it.
The whole point is with autosave, application state saving, and intelligent application closing, it shouldn't be your concern whether the app is running or not.
If you really need to know (i.e., for troubleshooting, or you're a nerd/control freak - like me, or most on here, no doubt), there is activity monitor, ps command, top, etc.
The average end user shouldn't need to know or care about this if the operating system works properly (i.e, it closes apps to free memory when required, pages intelligently, etc, etc).
Admittedly, there is some way to go, but that is apple's vision, and i seriously doubt they'll go backwards on that. iOS works this way, and there's no reason computers can't work that way too.
Needing to monitor what apps you have open is for nerds, and is not end-user friendly. When the user switches to the application it should open as it was before whether it was running at the time or not... whether it was active in memory or not is not something the user should be concerned with.
Just because computers haven't worked that way in the past, it doesn't mean that the old way is "right".