The Russian men's-singles figure-skating silver medalist (Plushenko?) was and is able to do "quad" jumps (four full revolutions in the air) and incorporate at least one or two of them into his routine. The American gold medalist Evan (drawing a blank on his last name) only did triples in his routine, but his overall performance was judged to be (slightly) better.

The Russian was quoted as complaining that, if the quad jump is not required for a gold-medal performance, then men's figure skating is "not sport, it's only dancing." Sounds a bit like sour grapes to me, and not only (I don't think) because I'm American rather than Russian. The whole enterprise IS "dance," or at least a mix of dance and athletics; the Russians/Soviets would never have become a predominant power in figure skating had they not incorporated their ballet tradition into the training program for this "sport."

I wonder if the quad-jump is some kind of unbreakable "barrier" in the sense that the four-minute mile was once erroneiously believed to be impossible to surpass.

The difference is that times for the mile (or for any running event) can be improved incrementally, a split-second at a time. Skating jumps MUST be increased in 180-degree, if not 360-degree, increments; you can't spin 4.0172 times in the air and come down without stumbling, you have to come down completely frontwards or backwards. The laws of physics just might, possibly, render completely impossible a five-revolution jump by a human being on ice skates, and maybe even a four-and-a-half revolution spin...