Elon Musk announces that he will put human beings on Mars in 10 years as a best case scenario, and 15-20 years. This comes shortly after the announcement of SpaceX's Falcon Heavy rocket, which is supposed to be able to lift twice the payload of the shuttle.
I don't know if the details of the mission are available - the one I know in detail is Zubrin's "Mars Direct" plan. The way he tells it, that sort of plan is the only feasible way for doing it. Not being an astrophysicist, I can't evaluate that.
Another Elon Musk project is Tesla Motors - the electric car company. There are substantial externalities that cause us to underinvest in interplanetary exploration, just as there are externalities that make us overinvest in combustion engines and underinvest in cleaner cars. But just as in the case of his Mars plan, Musk seems to be addressing the externalities in the car industry that the government bungles.
In response, I think NASA needs to announce a two tiered prize fund: one for the first party to put a human on the surface of Mars, and one for the first party to put a human on Mars and bring him back safely to Earth. And then NASA should announce its own effort. If NASA achieves either task first, it will distribute the prize between all the competitors.
A fun Mars Youtube video from Symphony of Science: