Add a Turnigy SK3 motor, some LiPos or LiFe batteries, sprockets and chain, an ESC, and a remote control and you're electric.
Print at 50% or higher infill with ABS (Edit print this as 90% or higher infill. I just broke the 50% one haha). Trust me on this one. I've broken probably 5 on these that were PLA or 25% infill.
Oh, an don't bother trying to print with support material. It's way easier to just print without support material and clean up a couple little imperfections.
See http://mrrocketman.com/blog/2014/01/27/electric-mountainboard-is-working/ for more details.