Neat. Do you actually need to move relative to your surroundings? If not, should researchers set up reverse treadmills? If you keep making the right leg movements, does it work from a chair?
As remarked on in the linked blog post, there seems a nontrivial likelihood that the effect is related only to visual processing, not general cognition. While Chatham hedges the visual processing idea a bit, I find it a more persuasive hypothesis than the other options. I can't really give this much weight unless it were demonstrated to have a similar effect on non-visual cognitive tasks.
On the other hand, if this is signicant I may need to take up reverse-pacing.
I'd wait for more study before taking this too seriously. As Chris Chatham also notes...
If stepping backwards is associated with the spreading of spatial attention (as seems reasonable - to make sure you don't fall over!) or simply with less acute vision than stepping to the side or forwards (as also seems reasonable - vision is probably better for objects that approach or stay the same than for those that at least momentarily recede), these effects could be just another demonstration of the well-known sensitivity of the Stroop task to vision and spatial attention.
From a recent Psychological Science,
In everyday life, individuals typically approach desired stimuli by stepping forward and avoid aversive stimuli by stepping backward... Cognitive functioning was gauged by means of a Stroop task immediately after a participant stepped in one direction... Stepping backward significantly enhanced cognitive performance compared to stepping forward or sideways. Considering the effect size, backward locomotion appears to be a very powerful trigger to mobilize cognitive resources.
As Chris Chatham notes,
This work is remarkable not only for demonstrating how a very concrete and simple bodily experience can influence even the highest levels of cognitive processing (in this case, the so-called "cognitive control" processes that enable focused attention), but also because performance on the Stroop task is notoriously difficult to improve.
When you suddenly realize that a task is more difficult than you assumed it would be, or when you face a particularly difficult choice in pursuit of rationality, you may find it useful to literally take a step back. For those of us who are particularly interested in making good decisions, this may also serve the purpose of self-signaling, as Yvain and commenters discussed earlier.
Chris's post has a link to a pdf of the paper.