Creating an Independent Music Site

I've been formulating a music site for independent musicians for exposure and distribution. I know the space is crowded with the likes of Magnatune and Amie Street. I guess what would hopefully differentiate my idea is my so-called secret sauce I've been incubating.

Of course being a developer through and through, it would be a joy to create and explore this whole undertaking. As of the moment, current recipe looks like this:

Main Web Framework
- Grails (but of course)

UI
- leaning towards GWT

Streaming Music Format
- XSPF

Streaming Music Media
- either xmlmp3player or musicplayer

Authentication/Account Handling
- considering exclusive use of OpenID via OpenID4Java

Social Networking Feature
- would support OpenSocial probably via Shindig

Hosting
- Amazon Web Services

Payment Service
- PayPal perhaps, unless Google Checkout starts serving the Philippines

Hope I find the time to start working on it. :)