Your comment caused me to think if something that might be done with nanostructures.
There have been some very big breakthroughs in materials science in the last few years, and there are more just on the horizon.
When you factor in the whole subject of Bose-Einstein condensates and really advanced things that have been done with lasers, nanoparticles, etc., it's not hard to imagine that the kind of people and resources that can be attracted by a top-flight company like L-M might come up with something really exciting.
In any event, I can't imagine that the senior management of L-M would put their company's prestige on the line with an announcement like this if they weren't certain it was going to work out.
As someone else noted, the L-M Skunkworks has done the impossible many times in the past. I would imagine that for every time they've done the impossible in a public way (as with the SR-71) there are probably three or four completely secret ways they've done the impossible.
I am well acquainted with he physics of stopping neutrons, as I said, it will be interesting to see how they do it. I, and you, expect something novel.
Physically, stopping a neutron creates a radioactive atom (n, gamma reaction) and a shower of gamma, followed by the decay of the activation product.
Traditionally, you stop a neutron with lots of hydrogen (like in water or polyethylene) or a combination of poly and boron or poly and cadmium, with a lead or DU backup to stop the gamma.
A newer approach would be welcome!