Kids, this is a really bad idea. I'm hoping these guys at least wore goggles, but considering they decided to break the glass with their bare hands, I don't think safety was the #1 priority.
Questionable methods (and music) aside, that's pretty impressive. The thinner iPad 2 glass is in fact stronger and more flexible. Of course, it's extremely unlikely that you're ever going to be flexing it — I'd be more interested in how hard it can take a hammer strike, or how far it can fall onto a corner without breaking. But that costs $500 per shot, so… perhaps not the best thing for a low-budget video.
The guys doing it are from iFixYouri.com. They are strong.