Personally I am not such a huge fan of going away from the nuclear power before renewable energy becomes massively accessible. I have just stumbled upon this article: To Slow Global Warming, We Need Nuclear Power that talks about this applied to the US.

I don't know how Germany managed it, but for Japan, I don't think they will be going away anytime soon. Right now, natural gas generators can easily supply Japan's demand, but I am not sure whether that is more expensive or how long it can be done.

My problem with nuclear energy is that the current technology used in nuclear reactors is technically unstable. unlike many other energy sources, nuclear fission is basically an explosion that is kept in control using various techniques. Since the chance of a failure is non-zero, we are always risking a radiation leak of some kind or the other.