I recently purchased three addiitonal Wiis for friends who needed them and, of course, registered them with Nintendo for the new straps.
However, what I got back was unexpected:

That's right: revision 3 of the Wiimote strap.
Notice the rounded head instead of the Wii shape like on the first two? Also, the choker point not only has a small raised grip on it but it is IMMENSELY tighter than the original two. If you always have the problem where your strap loosens during play, believe me when I say that this sucker won't be slipping anytime soon.
From the sounds of it, Nintendo was trying to produce these fast enough to get them out the door and as such resulted in a different factory line developing them.
It's a shame they don't carry the Wii look or logo because the choker actually does its job by keeping the strap tight, unlike versions 1 and 2 which the choker just slides away, allowing the strap to loosen.