Electric is the way forward but does require a better battery which is Lithium Air the holy grail of batteries these have the potential of 10kw/kg. In fact anything over approx. 3kw/kg is competitive on weight with Avgas due to the high energy losses with an IC engine near 80% losses with electric 5 to 10% so only 1/4 energy storage needed. Fast charging 80% is getting better see Tesla cars.
So what is needed for electric.
Low cost safe Lithium Air
Fast charging or a standard battery that can be swopped fast.
Airfield infrastructure for fast charging/battery swop and charge.
May be a 40ft container with a big cheap static battery with a 3 phase supply
just plug in and DC charge at a very high current DC better than AC.
So what is needed is what got the IBM PC going Standards
These are coming in Battery and charging infrastructure this will be from Electric cars.
To give you an idea GM is just about to launch a 200 mile no compromise full electric car the Chevy Bolt to complement their 50 mile electric drive ICengined Chevy Volt (100,000 already sold) the best car they have ever made.
So I believe electrics will happen but like all new concepts will take 20 years to arrive like the mobile phone.