The European Space Agency's (ESA) Mars orbiter (the Mars Express) has been a great success.  Its mission is expected to wrap up on November 30 of this year.  On November 9, ESA launched a sister mission to Venus... the Venus Express!  The ship is expected to arrive at Venus in about 4 months where it will orbit the hot planet and study its soupy, hostile atmosphere.  Check out the Venus Express Mission Homepage for more information.

Another interesting upcoming ESA mission (due to launch in June of 2006) is COROT.  This satellite will orbit the Earth and will include equipment which should be able to definitively detect terrestrial planets (i.e. consisting largely of rock, as opposed to gas giants) around other stars.  Up until now the only planets we've been able to detect around other stars have been gas giants like Jupiter, the largest and most massive sorts of planets.