Well, this isn't it exactly, but we just bought this fixture from cb2: http://www.cb2.com/pendant-lamps/lighting/firefly-pendant-lamp/f5281 . It's very similar and it looks fantastic over our dining room table. I'm very happy with it.

I would bet that this is a custom piece. I was able to google it with the information from the person who commented first and came up with an artist named Alison Berger who has some lighting pieces that looked very similar to this. http://www.alisonbergerglassworks.com/AllLighting.html#34
I would think that for a similar look and much less cost you could go with the Firefly pendant recommended above and you can find some very dramatic photos online where people doubled it up.

i really think they just bought 5 of the same pendant and had their electrician attach them to that ceiling plate. you can buy the globe pendant from west elm.

*6 of the same pendant

http://www.zincdoor.com/c/Lighting/Pendants.aspx