The decision to get rid of nuclear power is absolutely correct. The question is only with what it should be replaced.
Yes, exactly. But until a viable replacement is found our nuclear power plants should keep going. It was a totally dumb and short-sighted decision by the former government. "Well, let's just turn them off and worry about everything else later because umm... probably, well or maybe or umm... at least hopefully there'll be alternative sources of power production by the time the nuke plants have all been shut down and err.. if not we can always import power." Come on. That is plain retarded. That's like calling your heating contractor today and making an appointment in 2020 to have your heating removed from your home that year because of the possible effects of global warming by then.
Now, I totally agree that the decision to get rid of nuclear power plants is correct but only if and when a viable alternative has been found that can cover the loss of nuclear power by 100% at least (better yet 100%+ so we could export/sell our excess power to neighboring countries).
What should have been done is give the operating companies (of the nuke plants) an advance warning that a long term exit strategy is going to be developed. Then promise them big time incentives (tax relief etc.) for supporting the research of alternative power sources and redirect government subsidies from e.g. coal mining to research.
Then one day in the hopefully not too distant future when someone somewhere has found a way to replace nuclear energy, only THEN begin developing a concrete exit plan with individual operating periods for each plant (based on the age of the plant and the efficiency etc.) so that the transition is as smooth as it could possibly be.
This whole issue is a typical problem that is just not compatible with politics though. An election period in Germany lasts for four years so any political party will always just make short-term decisions/plans while the whole issue of an exit strategy requires super-careful planning and a lot of patience (years or possibly decades...).
Actually I think it would be best to establish a special committee made up of a majority of young, independent (yeah wishful thinking but as independent as possible) scientists and other members of the various interest groups. Then give the Bundestag (parliament) only a controlling/supervisory function. Politicians should just not be involved in the decision-making on an issue like that. The decision on the right point of time to drop nuclear power should be a purely technological and economical one (when it makes sense) and not a political one (when it helps a party to be re-elected).