I believe this is the Clark Ceiling Pendant by Wilmette Lighting. You can check it out here:
http://www.lumens.com/Clark-Ceiling-Pendant-by-Wilmette-Lighting/uu237311/product
The Edison bulb makes a huge difference in the look of the fixture. Love it! - Susan

The previous reply was helpful but not quite correct as the suggested light is an independent pendant light. I am really interested in finding the light shown that has multiple pendants suspended from the solid top piece. Does anyone know where to find this?

Try this. http://www.shadesoflight.com/laboratory-glass_pendant.html

I actually emailed architect. He said he bought them from a small vendor in Seattle who no longer carries them. He had the metal plate fabricated, which you could probably do with the above lights link I posted.

West Elm and cb2.com sell similar light fixtures