I definitely want some.
I'm surprised no one has mentioned the best part of these arms yet - horsemen.
As of now, Lego horsemen look pretty pathetic. Their swords are either straight up, or along the horse's neck (if you can get the arm to go down without pushing the figure out of the saddle).
With these arms.. horsemen could look like they'd actually be able to hit something from their horse.
So for my horsemen and "hero characters" - I'd definitely try to buy as many of those arms as I could.
Any idea when you'll be ready to start producing them? If at all, that is.