I was completely unaware that the UK has a probe on the way to Mars:
Britain’s mission to land a spacecraft on Mars reaches its first nail-biting moment today when the Beagle 2 probe is ejected from its mothership and sent hurtling towards the Red Planet. […] The British probe is due to bounce down on the planet at 2.54am on Christmas Day and begin its search for evidence of life.
Wow. Apparently it was launched just last June, presumably to take advantage of the conjunction. Good luck, chaps!