#GoogleMusicBeta and Ratings?

I'm still trying to get used to the ratings feature.
On the surface it seems to do what it's supposed to do. You can give a track a thumbs up or thumbs down. Once this is set, the track is added to the Thumbs Up auto playlist. Cool, I guess I can get all the songs I like in to one list. The downside is that I share this library with my wife, and what I consider a good tune does not always match up with what she considers a good tune. I can live with that.
Once rated, you can also sort. It looks like you can either sort on rated songs, where thumbs up are sorted first, then thumbs down, or you sort based on unrated. I guess another way to order and view my collection, but still trying to figure out a practical use for this feature.

What threw me, though, was I started building a playlist this morning. I went through, added a few albums, and started playing. A song came up that I didn't want in the list, because not all albums are winners all the way through, and instead of removing the song from the list I gave it a thumbs down rating. The song stayed in the list, but stopped playing, and skipped to the next.
I don't really know what's going on here, if the song will be played again, or just sit there in the list ignored because it's got a thumbs down. The help docs didn't shed any light on what's happened. I guess I'll just have to keep playing the list and see what happens.