I saw this simulation a few month ago and its realy incredible! vimeo.com/27431307
I tried recognize it in C4D a few times and it is my the third attempt. This is very fast render, so sorry for bad quality. I used realflow for simulation and TP for control size and color in c4d. Control colors of particles was realy hard task. Result is not very clearly with color.
If you want, I could make a short video about how to control some parametres of particles (like size, color, orientation etc.) depending on velocity (or other paramtres).
UPD: tuts vimeo.com/37515017