I have to admit, when I first saw it, I was like... "...?...", NOW, after watching the video, I am IMPRESSED!
I own a kayak for my water photography, and I searched far and wide for what I thought was one of the best kayaks for that purpose, but, I might have gone with this, had I known.
The one thing that I am not that sure about is how (for me personally) is that my truck has a topper on it, so that would prevent me from placing it in the bed of it.
Another thing is that I prefer to not have a motor of any kind, but, if I didn't, this would be a good boat choice for me.
As far as stability goes, this beats my Native Ultimate 12' I have, it's 'supposed to be' one of the most stable, but I'm not that impressed with that part of it. Getting in and out is not a good thing, especially when you have thousands of dollars worth of 'stuff' in it, insured or not.
The way you can remove that seat on this round boat though is cool, and I'd (personally) have a very short seat to be lower, the height of it is a downside to me.
Like what has already been said, laying down on it would be a good way to use it, maybe not all of the time, but it'd come in handy.
They need to install a rubber rim so that it'd act as a tire so when you do roll it, it doesn't do damage, they may do that, you never know...
For someone that doesn't want to spend the money this costs, an alternative could be to buy a two-man bass boat, they are REALLY stable, I've had a few (for fishing) and the only drawback for me on those is the weight, I'm a little too old to be lugging that kind of weight around. You can get them on Craigslist for around $400. pretty easy.
I'm really impressed with this though, and I may have to change my thinking and buy another truck just to haul this with! heheh
Thanks for posting this, it's VERY innovative, I'm going to be checking this out a little more, I really like it. 
Randy