The events in Japan indeed seem frightening and certainly give great pause to what may or may not occur. That having been said it seems the Japanese people have the most to risk/fear in all this.

A nuclear explosion is really not in the cards though radioactive contamination, though likely mostly highly localized, seems like a reasonable and looming result of the reactor containment structures failures.

While this doesn't paint a rosy picture for the future of the hundreds of thousands if not millions of local people in the area of the reactors as they could well be displaced from their homes for an indeterminate period of time, it seems this as well as the radioactive contamination of the area will be the most likely result.

What I've heard of TEPCOs history in regards to previous safety procedure and radioactive discharge events doesn't evoke a lot of faith in their abilities at containing this disaster but I also think they're being counseled by some of the top people in the industry now, which is a good thing.

The Japanese people have once again shown the high caliber of their societal makeup and have handled this huge disaster far better than many other places in the world would in the face of such a multifaceted disaster scenario.

My heart and thoughts go out to the Japanese people. Though they are a strong and stoic people, this is a disaster more dire than any people on earth living in such a densely industrialized/populated area have faced in modern history and they can use all the help they can get.