There was a kid over here who achieved a fusion reaction last month and is now the youngest person ever recorded to have done so
http://www.bbc.co.uk/news/uk-england-lancashire-26450512
Fusion would be the magnum opus of the energy industry, it would destroy all existing contemporary energy industries over a period of about 50 years as the technology was miniaturised and became safer. That would also lead to a massive shockwave in heavy industry, energy production and taxation revenues. The fossil fuel industry would die very quickly.
The problem with fusion is that fusion is infinitely achievable, it is just that we've only started to see the first signs of net yield increase in power from research Tokamak systems in the last couple of years - and even then they are somewhat fleeting. Requiring a small power station in order to generate a small power station plus a hamster on a wheel's worth of power output.
Clean fusion theory has the potential to be safer than fission, but we aren't there yet. Fusion reactions still irradiate
(be it in different ways
) and uncontrolled plasma bursts could be very dangerous. Basically we're looking at decommissioning lifespans in the terms of someones life rather than a couple of million years. Fusion creates free neutrons, free neutrons create radiation when they impact other materials - a la fission piles
(neutron reflectors
). Tokamak's also tend to be fuelled by Tritium
(Protium [-> natural Hydrogen] -> Deuterium -> Tritium
). 3H
(Tritium
) is highly radioactive. Radioactive material in = radiation problem.
The use of Tritium also creates an other false economy. While the Tokamac may produce more energy than is takes to fire the reactor, Tritium doesn't occur naturally save for in tiny quantities in the upper atmosphere. Thus it has to be engineered. Ironically if memory serves 3H is manufactured by placing Deuterium into a fission reactor - though don't quote me on that. So in order for fusion to genuinely have a net gain it must produce more energy than was necessary to both fire itself AND produce the Tritium. If the entire system relies on fission reactors, then we'll likely need more fission reactors in order to feed the fusion reactors. What we've really achieved is an even greater dependency on fission be it likely having eradicated fossil fuels in the process. Great news for Japan who are trying to cold shutdown their stock.
Cold fusion has always been Sci-Fi's answer, you don't need 8000k temperatures and it is still powerful enough to prevent radiation exposure. We aren't there yet and the last I heard, it was never likely to be possible.
But all in, yes, I think we should be throwing money at the problem. We should also be throwing money at higher burn rate fission such as standing or travelling wave reactors as we can throw fission waste into these things and have it cook that back into usable energy
(reducing its long-term radioactivity
). TW/SW in theory don't require core servicing, so potentially are much safer.
I think fusion reactor is crucial in years to come. 
