We recently set up a Myspace page for Vocoid, so if you have a Myspace account, come be our friend!
We searched the myspace ranks for artists we liked, so if you're looking for more music, we'd recommend you check them out. Links to their projects can also be found under the Links page under the friends section. We hope that, after we're finished setting up the site, some of them will be interested in contributing new content.
We're also looking into some 3rd party solutions for digital distribution for Vocoid so new artists (and maybe some of the current ones as well) will be able to sell tracks here.