For a person who usually has plenty of words at the ready, I have no idea what to say. Like everyone, I guess, I feel more or less struck dumb. Dumb & numb, I guess...
So I'll just pass along a few links where you can find continual updates on the nuclear situation in Japan.
Beyond Nuclear has tons & tons of info
Nukefree.org does too
Lots of good "Resources on Nuclear Accidents" here
Good compilation here on EcoSanity site
Union of Concerned Scientists - "All things nuclear - Insights on Science & Security."