NASA announced today that Curiosity has found complex chemistry in the soil of Mars, but no life, and no organics. Curiosity also found water in the soil, plus carbon compounds. Carbon and water are essential to life as we know it.
Whether the announced discovery is "for the history books" or not, as a mission scientist said it would be last month, probably depends on future developments. If it turns out Mars has never been home to more than interesting chemistry, this discovery might be footnote material. However, if it leads us to life on Mars, either extinct or extant, then that scientist will have been proven correct.