Just to clarrify, the majority of new shipments of wii's will have the new strap as standard, so if you buy your wii after this point, you should have the new strap, if you are unsure, a picture can be used to clarify:
http://www.nintendo.com/consumer/straps.jspThis especially applies to people who buy their wii's in January or after, by then most wii's will be from a new shipment.