What did she say? She said that the recent earthquake in China may have been "karma" -- cosmic justice for the way China has treated the Tibetans. That's stupid, but the theater owner -- Ng See-Yuen -- wasn't angry at the manifest silliness of Stone's statement so much as the fact that she's politicized a devastating natural disaster. Which is kind of a good point too -- at least, she's politicized it in a way that's really weird. And it's important to note that, at least on its face, this doesn't seem to be a case of the Chinese government censoring Stone's films, but rather an exhibitor making a choice not to show them. Of course, with the way the Chinese government operates, who really knows.
Sharon Stone seems to have no "big" films in the pipeline, so it's not clear what effect, if any, the boycott will have on revenues.