What do challenges from the skeptical movement have to do with Science?
Not to disagree with the others who've said, "Nothing", I'd say such challenges are a good way for the non-science public to separate the wheat from the chaff. If a skeptic was to issue a challenge to a scientist who was promoting a breakthrough that, while seeming to violate our understanding of physics, was in fact a real breakthrough, he'd be able to meet the challenge and win.
It's the ones who have nothing and
know they have nothing who would shy away from a challenge.
Consider two announced breakthoughs from a few years back: Cold Fusion, and High Temperature Superconductors. Both of them, if they were to be real, would involve serious changes to our understanding of some basic physics. Not as much change as "free energy", but certainly Nobel Prize level work.
CF went about their announcement is a manner very similar to Steorn - No formal publication, just press conferences will very little actual detail. HTSC published their work in traditional journals, with enough details that anyone with the right skills and a lab could try to reproduce their work.
Guess what? Cold Fusion was a bust. High Temperature Superconductors worked for anyone who tried it. In fact, in very short period of time, people were producing new results, new types of superconductors based on the inital work. That's how science works. If what they have is real, it'll work for anyone, not just them, and other labs will quite quickly start expanding on their new fields of understanding.
The fact that they're not willing to trust in the systems that have brought science so far, is pretty damning.