I agree about the unsprung weight concern (I've been thinking about that problem with electric direct drive since oh, about 1976).
I think with alloy wheels, permanent magnet rotors, aluminum wire, ironless stator electromagnets, and an aluminum hub/knuckle - the weight could be reduced considerably. Of course for high performance handling, inboard mounted motors with cv/drive shafts may be inevitable for now.
An active/preemptive suspension like
Bose proposed in 2004 (again not too new) could make a big difference too. A friend who works at Bose said he saw a demo of a car driving over a huge curb: it just 'melted' over it like it wasn't even there. So cool.