Not that I am a fan of it, but I did watch my first Formula E race the other day whilst I had nothing better to do. It was in Mexico City at the Autodromo Hermanos Rodriguez. The same place where F1 races.
They created a shorter track for the Formula E cars wherein there is basically a clockwise oval with a few chicanes here and there. The first turn (right) is immediately after pit out and cuts across to the back stretch.
What I found interesting, though, is a reconfiguration of the twisty bits inside the old baseball stadium. I immediately wondered if F1 was to use this configuration, but also thought that maybe the F1 cars might be too fast for it.
On www.formula1.com a layout of the Mexico City circuit is illustrated and it is the same as last year.
To view the reconfiguration for the Formula E race, just check out this short youtube clip. They enter the stadium around the 50 seconds mark.