NASA's Phoenix probe successfully launched today and is on its way to Mars. It's due to arrive in May 2008 and will undertake analysis of the polar region of Mars, the first probe to do so. There;s plenty of information on the mission around on the web including this excellent taster video on youtube.
[If you're reading the email CAS News you'll have to follow the link above or go to the CAS News blog to see the embedded video].
Also this video includes more details of the mission and of course there's plenty of details on the mission website and also the Planetary Society website.