Really cool!! One of the things I like most about Physics is the totally non-intuitive consequences and phenomena that arise from very simply looking physical systems. The article makes it sound like it is more that what it actually is because even though it is really cool to watch, it really isn't much of a mystery when you consider two things: first, the slinky is falling even though it might not look like it, because it's center of mass is falling and readjusting itself all the time. You can see this in the second video, it is the red dot in the computer model. And second, the top part of the slinky is holding more weight than the bottom therefore when released it will fall faster towards the bottom one. I'm pretty sure that there is a lot more to it, but this should be enough to grasp the basics of what is going on.