I decided to go ahead and start a "Music 2.0 Directory" over on Wetpaint - since my tagroll of companies is growing so fast. It is a wiki, so everyone please jump in and start adding your companies. I've only really built out the framework right now, but let's see what we can do with it.
If it starts to take off, I'll get a proper domain for it and clean it up a little. Ready, set.... go!