Yep, I'm seeing something very similar. It's my work machine, so I don't have access now for a screenshot (funnily enough it hasn't affected the one home machine I tried it on).
My symptoms are pretty well aligned with yours. Frequently (almost every track), the song starts, then goes silent, but the slider keeps going. Sometimes it comes back after a while, sometimes it's when the track changes.
I also noticed sometimes that the UI gets out of sync with what's actually playing, displaying the wrong track. One other oddness I noticed also was multiple tracks playing; i.e. if I repeatedly skip tracks, it can end up with three/four tracks playing. I left it like this for a while yesterday to see what would happen. After a while the Rhythmbox UI became unresponsive, but the music played on until the song(s) finished. After that I gave up and played music on my phone as I needed to get some work done. :-/
I'll submit a bug on Monday if there isn't one done by then.