Amazing...

wow, i can't even conprehend how this was done in flash. here
Amazing...

I'm going to take a wile guess and say first they animated it as a solid mass, with no opacity changes. They sync'd it up to the soundtrack. Once it was finished, they went back and played with opacities...

Chances are, that animation was done completly in action script. That doesn't look anything like tweening.

hmm, after looking at it again, i'd probably think this:

Could be loads of movieclips duplicated/attached in a specific pattern with different rotation settings. I have seen that kind of movtion before but it didn't look anywhere near as good.

or

It took a while to initialise though: 'Prepairing' slowed my system down for a while. Could be a load of movie clips mapping out the shape of another movie cli[ using hitTest with a shape flag. takes a while to initialise but the result would be a more organic less mathimatical pattern.