While I agree with you that decentralized power will be the way of the future, there's no way the US, where California alone is larger than Germany, can make such a drastic and impressive transition in even a tenth of the time it takes Germany. The power grid in the US is one of the (if not the) most complex networks/systems the world has ever seen. Heck, it's not even a "singular" entity, with three interconnects spanning parts of Mexico and Canada comprising it. We're not going to easily transition away from this--not that I'm saying we shouldn't try. Our current infrastructure is not capable of handling mass amounts of renewable (read intermittent) sources of energy--the energy storage technology, bi-directional communication, and security measures among other necessities just don't exist yet. And while at a certain point our country needs to make the leap and take the risk, we should also be cautious about trying to brute force a solution--look how Spain's renewable energy investments are paying off.
Edit: It may also be too early to call Germany's energy plan a success. They still face many substantial challenges moving forward (http://www.economist.com/news/europe/21594336-germanys-new-s...)