I used to think Songbird (now Nightingale) was going places. I remember being so excited when Songbird 0.1a came out! Unfortunately things went downhill after a couple of years until POTI killed the project and progress on the community fork has been excruciatingly slow. I want to get involved, but its hard to know where to start.
Nightingale is what I actually ended up using after I failed to convince foobar2000 on the subject of self-signed SSL certs. A little flaky on occasion, sure, but for my relatively simple purposes, it worked nicely.