There is lots of chocolate out there that doesn't have milk. Semi-Sweet and Bittersweet are often dairy free.
Rose Levy Barenbaum has a sour cream ganache frosting which I made a time or two with Tofutti's Sour Supreme (or Better Than Sour cream--I can't remember which) It is not really meant to be a pouring consistancy--she mentions that it pipes well, but if you used it a little warmer and maybe used a little additional "sour cream" I wonder if it would pour.
You could stretch it out by adding some cocoa butter and some powdered soy milk. I agree it is very sweet. This is what I plan on trying as soon as it gets cool enough in FL to order the vegan white chips and cocoa butter. LOL
Like Sadsmile said...non-dairy does not mean dairy free. It may be ok if someone is just lactose intolerance, but not ok if someone is actually allergic. The standard brands grocery stories carry say non-dairy but they actually have Cassein (a milk protein) in them.
I have a weird non-allergy reaction to milk and the non-dairy creamers still manage to affect me just as much as yogurt or cheese would.