Here are some marbling that gave me a few ideas.
What if we have a background marble with traditional animation on top. that way the traditional animation whouldn't have to be intricate because theres already something goin on in the background.
or
have several marbling papers and mask them with shapes in after effects or flash. Then we could animate those masks. Like this but more abstract :)
http://www.youtube.com/watch?v=wlItj3nlkqo

Here are marblings with masking and paintings on top
http://marbleart.us/Kiwi.jpg
http://marbleart.us/Jeff.jpg