It has to have Long John type of frame because it is relatively narrow to go to places where normal bicycle will go.
It must work in winter too. Moisture and freezing problems gotta be solved for electric system. Frame and fork must be capable to fit plus 50mm wide tires.
Electric assisted is excellent choice for people who just want to transport not to sport. Battery enables real electric system in it; lights, nice horn and even turn lights and sound system. There's gotta to be good permanent lights in it, you gotta see the road details instead of just being visible.
It might look good and be light too.
These Urban Arrow people are very near, they got Eurobike 2010 award for it and they are selling it in here.