[moxy]

While I'm pretty sure this doesn't offer the intellectual discourse you're looking for, http://cherrypeel.com utilizes a very reddit-style voting system to promote underground, independent music. I've discovered some fantastic new artists from this site.

[wastedbrains]

right after I posted I saw that I had missed you already recommending this site. Yeah not the disourse, but a well done and interesting way to find good new music.