The quest for a viable fusion reactors is now over 50 years old, it has been going on for so long that the joke among nuclear scientists is: "viable nuclear fusion is just 30 years away, and always will be!
The quest is going on, nonetheless, because, if successful, it would provide unlimited power through a process that mimics the one that is powering the Sun and indirectly our life on Earth.
By fusing two hydrogen atoms into one atom of helium you "save" a bit of mass that gets transformed into energy, E=mc2 ... remember?, in form of heat that in turn can be used to power a turbine to generate electricity.
The first fusion reactor (or better a controlled fusion experiment) was Shylla I and took place in the Los Alamos National Laboratory back in 1958.
Since then many fusion reactors have been tried but the stumbling block has been controlling the fusion process without using more power than the one produced.
Now we are approaching the time when a real fusion reactor may become available, the ITER, under construction in France at the staggering (estimated) cost of 35B€ (as of 2015 the cost is already 14B$)! Notice that ITER is expected to be completed in 2019, with full deuterium-tritium fusion starting in 2029 and deployment on the grid in 2040... Hence, we are still far from saying that we have commercial fusion power.
On the one hand ITER should provided power in the order of 2-4GW at very very low fuel cost. On the other hand if you look at the cost of building the reactor the cost of power will be astounding! Clearly, the hope is to learn from ITER and have much cheaper reactors built in the second half of this century. And technology evolution is promising, at least if we learn from the past, progress in both performance increase and cost reduction.
This is where the news coming from MIT fits in: using commercially available superconducting materials they have designed a new fusion reactor that should be smaller in size and complexity dramatically cutting the cost and moving its implementation to the middle of the next decade, that is before the ITER will start experimenting with deuterium/tritium.
The new superconducting material almost double the intensity of the magnetic field used to contain the fusion process and this improves the efficiency (the production of energy) 10 times.
So the end of the rainbow may actually be reachable after all!