There's no doubt that the US can learn from the shear audacity and willingness to invest in our country's long term energy plan like Germany has done with the Energiewende. However, we can't pretend that Germany, in terms of its size, existing infrastructure, and structure of the electricity industry, is at all comparable to the US.
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...)