I just came across this article for those of you who have read it yet. It mentions that the winning submission for the new World Trade Center project was designed using Vectorworks on a Macintosh. This was really surprising for me as I've always heard the myth that Macs were poor for CAD work. Well, I guess that's not entirely true. :-)
http://www.architosh.com/news/2005-0...mac-bimop.html