The first SimCity post-release DLC is the Nissan LEAF Charging Station, out today.
It's a free in-game item that sounds like a dream come true: it produces no sewage or garbage (and so is pollution free) and provides a one-time wave of happiness to nearby businesses.
It doesn't take power, water or workers away from your city, either. Plop one down, zoom in and you'll start seeing a percentage of your Sims across all wealth classes driving the electric vehicles.
The idea is your Sims will drive their Nissan LEAF cars to the Charging Station to re-charge them. When they leave they will be happier.
Download instructions are over at EA's forum.