Hawker 800 Wing Oscillation (Language)

Found this video of a Hawker 800's wing oscillating...anyone want to hazard a guess as to what the actual cause is? My guess is it has something to do with the winglets...

http://www.youtube.com/watch?v=6mbIRXnCSts

I don't see the problem. I see birds do that all the time.

That's a funky winglet.

Aren't the non-winglet versions also prone to this, too?

that's what I thought I read...I wonder if it's aileron flutter? It seems like it's pretty uniform in both wings though from what the video shows.