Human settlement of Mars in 2023.
What do you think? Likely?
I doubt it myself.
http://mars-one.com/
Well yes and no. Mars is nice because it's practically habitable already. It has hydrogen, carbon, oxygen and nitrogen in abundance - we just need machines to separate those elements from the compounds they're locked up in. CHON - the elements necessary to maintain life*.
Also, going to Mars and establishing a settlement will probably work out to be much cheaper than a round trip. Simply because you don't have to carry your return fuel with you. It's a truism that in space flight, you need an awful lot of fuel to move a little mass. To make it a return trip, you need a crazy amount of fuel to move the enormous amount of fuel to move the awful lot of fuel needed to move a little mass. If you don't need return trip fuel, it works out much much cheaper.
In principle, there's nothing stopping us from doing things like that right now. It's just money and politics. Politicians will get squeamish about the idea of sending human beings on a one-way trip, but in reality, I doubt there would be any shortage of people who would volunteer for it.
*Edit: and that's to say nothing of all the metals and other elements in abundance there. There's no shortage of iron, so if the machines break, we could in principle manufacture replacement parts in situ.