While this does have a certain "coolness" factor to it, I really don't see the usefulness in it.
Yes it is still a "slim" but it doesn't exactly fit in your pocket. So there's some lugging of this large device around. Not only that, the power requirements for a ps3 aren't exactly light. I'm not sure how long a battery pack could actually power it before going dead, but my money would be on 'not long'.
Also, where exactly are you going to use this thing? Aside from the home, it just doesn't seem like there's many convienent locations. I can't see myself going to a coffee shop to set this up, when I could just as easily do in the comfort of my own home. And while yes, I understand that the japanese like to show off their latest gadgets, I just don't see trying to farm gil for my ultimate weapons in Final Fantasy 13 while sitting on a crowded subway.
And for a portable blu-ray player, that's been done way better than this setup. And cheaper too.
But still, kudos for the 'coolness' factor.