There's a possibility that it was done using Particle Illusion. This is the "secret weapon" of the visual effects world. It's cheap, and it can do some killer effects. Essentially it's a 2D particle system that just spits out small bitmaps which can be custom made by the user, or one can use the extensive libraries which come with it.
Check out the website and see what you think:
http://wondertouch.com/
There's also the possibility that it was done using FumeFX in 3D Studio, a real-world smoke and fire simulator that is hard to match for realistic (and surreal) effects:
http://www.afterworks.com/FumeFX.asp?ID=13
Joe Bourke
Art Director / WMUR-TV
