Nuclear power is clearly unsafe, it's just a question of whether or not it is more unsafe than the other alternatives. This accident doesn't need to prove that, the fact was apparent the first time someone lit a match.
However, Nuclear Power does have a special need to prove its case in the aftermath of this incident. Just look at the economic damage from the Fukushima issue. Other than the flight of foreigners out of Tokyo (fear + uncertainty is inevitable with the notoriously closed Japanese nuclear industry), there are issues with farming in Japan's third or fourth largest farming area, medium-term damage to energy output ("All eggs in one basket"), damage to businesses in Tokyo & environs (Rotating power outages, etc..). Summer in Tokyo will be HELL without air conditioners.
I think It's pretty obvious Japan needs nuclear power. A future without 20% of Japan's energy sources is a non-starter. I'm sure the power-downs & practical alternatives (fossil fuels) will show that decisively.
However, putting so much generating capacity in one location in an earthquake & tsunami prone country is a mistake. Maybe mini-nuclear plants are what we need going forward. Maybe we need less nuclear and more renewable power. Maybe something else.
However, what we don't need is people outside of Japan using this life-and-death situation to promote energy politics, be it green, nuclear or otherwise. The geographical & historical context is completely different. (Ontario will never be hit with giant 8 meter Tsunamis after a 9.0 earthquake.)