Uh, no, not really, a run away fusion reaction has never really been a concern. In fact, that's one of the biggest advantages of a fusion reactor vs. a fission reactor. Fission is a self-sustaining reaction, once it starts you have to work to stop it (via injecting a mediator to interfere in the fission reaction), where as fusion requires constant energy input in order to maintain the reaction. The part that "always seems to be 30 years away", is achieving a fusion reaction that produces more energy than it takes to maintain (allowing some of the output energy to be siphoned off to maintain the reaction). There have been a number of techniques attempted to achieve this with the holy grail being so called "cold" fusion, where cold is defined in this context as something less than the surface temperature of the sun. It sounds like the ultimate solution to the problem though is simply better magnets, not cold fusion at all.

Assuming this pans out, the real thing needed to make this viable as something other than a novelty is how much more efficient the reaction can be made. After all, if the output energy is just barely over the input energy you'd need to scale out to ridiculous extremes to produce enough usable energy, but if it's a significant amount higher then that makes more modest size plants viable.