+Car and Driver Magazine is reporting that new +Audi International R&D boss Wolfgang Dürheimer has paused the development of the battery-powered R8 e-tron and may kill it entirely. 

Apparently the cost of the batteries needed to provide the combination of range and performance needed for the R8 remains way too high. 

I wouldn't be surprised to see the R8 BEV scuttled and instead replaced with an R8 e-tron quattro using the same flywheel hybrid system that served Audi so well this year in winning at Le Mans. Dürheimer was still in charge of R&D at Porsche when they developed the 911 GT3R hybrid with the flywheel system in 2010. http://www.popularmechanics.com/cars/alternative-fuel/hybrids/porsche-911-gt3r-hybrid-flywheel

Since the original 911 raced in 2010, the flywheel unit has been shrunk to half it's original size and weight and it could easily fit into the front luggage compartment along with the motors that drive the front wheels. In the hybrid 911 racer, fuel efficiency was boosted by 30%. 

In the 911, the flywheel could provide 163 hp of boost. Imagine combining that with the 350 hp, 4.2-liter diesel V8 from the A8 sedan and you could have a really high performance sports car that is also very efficient, and much more practical than a battery powered version would have been.