10th Planet
Well though it hasn't been declared as a planet (yet). The recent discovery of an object larger than Pluto (PDF) has been of great interest. Of course they have been talking of the object for a while but the confirmation of its size gives some weight to validate it and invigorates that curiosity of space I've always had. I expect they will classify it as a planet; rather than demoting Pluto to a large asteroid. I wonder if they'll stick with Xena or go with another name... UB313 has a sort of Aliens feel to it :).
Also; this strangely makes me want to play Traveler again.