The "electric airplane" project to replace lots of hydraulics with electric servos has been being talked about for at-least 10 years, probably far longer. Not to say it isn't a good idea, but not particularly new.
As to flying a light aircraft entirely by electrical power. That was done in the UK by Cranfield University in 1996. The aircraft was a Chaser single-seat microlight flown by Nigel Beale at Kemble. There's quite a good article about it in "Engineering Technology", pp38-41, July 1999.
But, the Cranfield project used batteries, which was rather heavy. I suspect that fuel-cell technology would work rather better. I just hope that Boeing don't spend too much time re-inventing the wheel.
G