The Curiosity Rover was launched on November 26, 2011. The same year a major earthquake caused a tsunami east of Sendai, Japan that caused the second worst nuclear disaster in the world. The same year, Osama Bin Laden, FBI's most wanted man at the time, was killed by U.S. special forces in Pakistan. Many important things happened that year, although the Mars Curiosity Rover was just as important.
The Curiosity Rover is equipped with the most modern technology including a ChemCam, which helped with determining methane abundance and whether or not Mars ever held life. It's also equipped with an environmental monitoring system which helps measure the planet's humidity, pressure, temperatures, wind speeds and UV radiation. The list can go on and on, although it is certain that this Rover was equipped with the most recent technology available.
The mission allows for a chain of innovation to continue. Every mission allows to make improvements, which make missions like this possible. The chain allows NASA to push it's boundaries of what was previously or currently possible. Sadly, NASA hasn't shared what improvements this mission will allow them to make, although I'm sure they will reveal this information shortly.
The mission proved successful when the Rover was able to achieve it's main goal - prove that Mars could once have supported life. It also proved that Mars has the presence of Sulfur, Nitrogen, Oxygen, Phosphorus and Carbon, all of the key elements for life! This mission is amazing since it allows us to actually see the terrain of a planet that is anywhere from 34 to 250 million miles away (depending on where both Mars and Earth are in it's orbit). It is even more exciting to discover that the planet once, maybe even currently supports microbial life. All of these findings allow us to eliminate the feeling that we are alone in the universe and fires up our hopes of finding alien life.