Saw that last week as well. Looked into buying one even, found a few suppliers.
In my case though, with pets and small kids in the house, and all the males in the house with the exception of the cat being huge science and sci-fi nerds ... this would be one horrible purchase to make (to be filed alongside other epic mistakes of judgment such as "bought the 6 year old a real lightsabre and he accidentally cut his grandma in half"
http://youtu.be/TXMX_xm7IRo ).
Obviously you have to be extremely cautious: reflections from the glass are possible so nobody can be in the room with you, including pets; steps to be taken to keep fish away from the spot so they don't get instantly blinded or burnt .. and so on.
I'm also curious if the beam passing through the glass might do some residual damage there as well, perhaps creating a weak spot?
Cool idea though in theory! Come on, it's freakin' LASERS!