I'd be mad if this happened...I like Yao and I'd have to dislike him if he were on the Cavs.
I don't think this would make the Cavs that much better, though. They already have a sort of Yao-like center (really tall, can hit midrange shots and finish near the basket, but gets pushed around kind of easily. Yao is of course much better than Big Z, but I don't think he's what the Cavs really need.
Not to mention that Yao can't seem to finish a season because of injuries.