Yup. The Phoenix Mars mission has discovered that it snows on Mars. News release on their Web site. They also have this video showing clouds on Mars — and although they don’t claim it’s snow, in the video you can see occasional white schmutz blowing by the camera.
I grew up on science fiction stories that talked about life on Mars. Planetary science long ago demonstrated that the Martians of H. G. Wells, Stanley G. Weinbaum, and Ray Bradbury are nothing more than fairy tales. Now science is showing us something even more fascinating than the old science fiction stories:– the existence of frozen water on Mars, and the possibility that Mars have have seen liquid water in the past; all of which suggests a possibility that Mars once had life forms of some kind.