I love the idea, but not its implementation.
Rating stars should really be a configurable element just like everything else up there. I use a lot of useful (to me) information in both lines of the player display, and these rating stars tagged on the end of the lower line like that kind of unbalances things a bit.
99% in agreement with Rob re. image thumbnails. Being able to rate an image via thumbnail text would be handy. Not so sure I'd use that during a slideshow though.
Rating images for me is an interesting thing, still in its infancy for me.
With audio, I'm at the stage where I have both feet firmly in the "give us half star ratings" camp. I would make good use of a system like that.
So far, I'm finding that with images, the GHammer approach to ratings is all I need...
1's are awful, 5's are exceptional for one reason or another. that's it.