Well, I think e-assist bikes are already C&V, depending on your perspective. A riding buddy of mine just outfitted his 80s Fuji commuter with
a Copenhagen wheel. It allows him to shorten his commute by nearly half, arrive far less sweaty (and his profession requires that he's constantly interacting with others), and continue to ride the kind of bikes he wants to ride. I took it for a spin last week, and it's a pretty weird feeling, like the bike wants to accelerate far more than I was ready for!