It is perfectly possible to stand on it if it is powered. The same you can stand on a Segway: As long as it moves itself under your center of gravity when tilting. That would then also be the steering.
I like the idea (my kids would love it). It certainly has marketing value and calls up dreams of an amazing future, but there do seem to be some real practical problems (as the parent alludes to). Stopping seems particularly exciting.
From what I gather, the board would apply a single linear resistance (vertical) aswell as resistance from every rotation axis. So theoretically, we enough skill, you could balance yourself on the board purely by using rotational resistance, even without the directional friction I just mentioned. You couldn't jerk your legs forward and backward, but you could push on the ball of your feet to shift backward, and push on your right foot to shift to your left.
Am I making sense?
Where'd you read that? All I read was that they are working on a friction-free car.
It uses super-conductivity to facilitate levitation. Flux pinning creates an 'on-rails' movement between the two components (the superconductor and the magnetics on the ground).
Defects in the magnets and gaps would create areas of resistance, much like they do in toy-scale versions of this same concept, but you'll still be pinned to the magnetics as long as that superconductor stays cold.
There will be no 'astronaut-in-space' movement, because the board will only be able to achieve quantum levitation over a bed of magnetics, which will be many pieces and not defect-free.
http://quantumlevitation.com/the-physics/
http://www.ted.com/talks/boaz_almog_levitates_a_superconduct...
As others have pointed out, it depends a bit on how much lateral force you can achieve through tilting and reaction forces, but if you can balance a quadcopter, you can balance a hoverboard. It gets a lot easier if your load is attached to the platform.