Please consider partnerships with folks such as this:
<a href="http://community.roll20.net/discussion/2540/my-fantasy-art-kit-kickstarter-project-tiles-tokens-for-use-with-vtts" rel="nofollow">http://community.roll20.net/discussion/2540/my-fantasy-art-kit-kickstarter-project-tiles-tokens-for-use-with-vtts</a>
Having their art available as part of a subscription service would be fantastic. I'm sure there are other implications and legality details to work out but ones worth addressing IMO.
I'm rooting for Roll20 and as soon as I find a group of people to play with who are willing to use the service, I will be adding my financial support.
-Chris