It is high time that we start exploring and teraform some new planets. Maybe by 2100 mars is just another tourism destination. At the pace we move right now with all the technology that we have , is actually very slow. Things need to step up concerning space and other extraterestrial stuff.
NASA will have a programme that goes to and beyond 2018 so this is less of an opinion and more of a schedule question. We will get to Mars soon but whether it is by 2018 is simply a question of technological development. On balance i think that we will.
I do believe that NASA will put astronauts on Mars. However, it is important to remember that there were 17 Apollo missions and it took until the 11th for man to land on the moon. I will grant one thing that is different from 1969: our technological capabilities have grown exponentially. We have a much better chance at putting feet on the ground the first time than we ever would have with the technology for the moon landing. However, I think 2018 only gives us three years and I don't think we're quite there yet. A decade may be a more realistic timetable.
NASA is definitely developing the technology to send people to Mars, but it's unlikely this will be enacted and ready for a manned mission by 2018. There is much planning and preparation that must be done for such a large-scale mission and I would say we'll need to wait until at least 2030--or later--to see men on Mars.