Ha! I had almost the same conversation with my boy today (who I'm pretty sure has no idea he's getting one)!
If you are willing to open the box and get the serial number of your wii you can go to the Nintendo site right now and request your replacement strap(s). I'd recommend getting 2-4 since you'll probably buy more controllers than just the one that comes with the set. Also -- you can look and see if you even need the strap, since that box is open: on the site they show the new strap, which they started shipping with sets in December. So depending on when yours was produced you might not actually need a replacement.
We played DDR for nearly an hour in the arcade today and now I want one of those for the home too! I'm addicted -- and it's the only game I can beat the boy at. Maybe I've found a piece of home exercise equipment I'll actually use...
