This was announced about a month ago but it's well worth mentioning here. The Spaceward Foundation has once again teamed with NASA for the Mars Robotic Construction Challenge. This is really exciting news as it adds another piece to the exploration to do puzzle.
Here's some of the reasoning behind this challenge. You can read the rest and the rules on their web site.
Suppose we want to build a fuel/oxygen generation plant on Mars, comprised of an ore processor, a reactor, and storage tanks. Or suppose we want to build a human habitat, comprised of several interconnected habitation and support modules...
With today's technology, we already know how to build the basic machinery, and we also already know how to send payloads to the Martian surface... The problem is that we can only send up to a ton or two at a time. (The Spirit and Opportunity packages only weighed about half a ton each), and so have to assemble the structures on the Martian surface - with the human operators still on Earth!