After you rated a media item, an alert showed at the top of the screen saying "Your rating has been recorded" so, yes, your rating worked.
If you attempted to re-do it, you would have a notification on the rate window explaining that the rating would replace your existing one.
Your rating would also be recorded and viewable from the "1 ratings" link which pops up an overlay.
Currently the behaviour of that row of stars is the same as the Resource Manager.