News From Mars: Curiosity Has Discovered Something: NASA Won't Say What
Link: Big News From Mars? Rover Scientists Mum For Now : NPR
What are your thoughts on what the discovery could be?
...They have some exciting new results from one of the rover's instruments. On the one hand, they'd like to tell everybody what they found, but on the other, they have to wait because they want to make sure their results are not just some fluke or error in their instrument...
My suggestion: Larger than expected reserves of water [boring I know]