Looked at it again, and now I'm sure it's crap. Spokes don't break at the nipple (ok, 99% of the time they don't), so it's pointless. Spokes come with nipples anyway, so pick your spokes. If they are Sapim and come with these, I guess it can't hurt. I can't help feeling that the holes in the rim have a role in what angle the nipple is at, anyway.

The self-locking thing could be nice, whatever it is.