Outside of specific applications we aren't going to see a plugin helicopter any time soon, we are still too far away from getting light-weight, efficient power storage.
Hybrids, on the other-hand, is a more interesting area.
The use of motors to power the tail rotor (ala Bell EDAT), or for supplemental and emergency power requirements are more practical uses.
In mainstream applications, the integration of electrically driven systems will be more evolution than revolution.