Just weighing-in here my own opinion:
Of course I agree with weatherproofing, and that should be a given... but for me, I'd really like the Big Three (Kingsong, Gotway, Inmotion) to bring us options that have MORE power & torque (which I equate with SAFETY & fun, not necessarily speed, as I'm fine with 50kph) -- along with STABILITY (I'm not a fan of wobbles), but without making it as big as a tank. Sure, the Monster is powerful and stable, but it's also so massive that it loses nimbleness and quite a bit of convenience of being able to get up and down stairs as well as off-road capability. This would likely mean a compromise of battery life, but hey, we already have wheels with massive battery life, and I rarely ride more than 25 miles on a charge.
What I'm looking for might have specs like this:
18" wheel for STABILITY
40 pounds or LESS!
In the car world, this is more of a Ferrari than a Camaro, if you get my reference.
And if it looked more like a Ducati and less like a Roomba, that would be a plus too.