In an interview with NPR, John Grotzinger, the principal investigator for the Mars Curiosity rover mission, indicated that the data [that they are getting from Mars Science Laboratory Sample Analysis at Mars Instruments] is gonna be one for the history books. It’s looking really good. The announcement will be in a few weeks after more tests and confirmations are run.
Discovery News -One of the prime mission objectives is for Curiosity is to understand the past and current habitability for life on the Red Planet. Curiosity can not directly detect the presence of Mars life, but it has been kitted-out with miniature laboratories capable of not only establishing what materials soil samples contain, but also whether the Mars soil contains carbon-laden organic molecules.
Should Curiosity detect these organics, the mission will have confirmed the presence of the building blocks of life on the surface of Mars. This does not, however, infer the genesis of life on Mars, it just means that some of the ingredients are there.
According to this NPR article, Grotzinger refers to the SAM data as being the source of the excitement. Indeed, one of the instrument’s objectives is to address “carbon chemistry through a search for organic compounds, the chemical state of light elements other than carbon, and isotopic tracers of planetary change,” according to the JPL mission site.