Okay, so the Curiosity rover landed on Mars is going to start doing science pretty soon. Or whatever. At this point, it's old news, and NASA has already moved on to its next mission to Mars, a lander called InSight.
InSight, which unusually for NASA doesn't seem to stand for some crazy amalgamation of scientific terms, is going to Mars to try and figure out how and why Mars ended up so different from Earth from a geological perspective. For example, Earth has tectonic plates. Mars definitely doesn't now, and probably didn't before. We're also not even sure whether Mars has or had a liquid core like Earth. Kinda basic questions, and InSight should help answer them.
InSight is a sort of a multinational mission, with instruments coming from a few other countries. The French will provide an instrument that sits very very still and does nothing but listen for even the quietest of Marsquakes, while zee Germans are contributing a beastly robotic drill that will hammer its way 30 feet into the Martian crust to measure heat flow, whether the crust likes it or not. Appropriate, somehow. For its part, JPL is kicking in the actual spacecraft, the robotic arm, and some cameras.
At just $425 million, the InSight mission is as cheap as it is (yes, $425 million is cheap) because it's basically a minor to moderate redesign of the Phoenix lander that operated on Mars for a couple months back in 2008. This means that the landing will be mostly drama free, with a conventional powered touchdown, no sky cranes or airbags necessary. InSight is scheduled to launch in March of 2016, and will land on Mars that September. It should operate for at least two Earth years, and you can see what it's planning to do in the animation below.