Gamestop might know, as they recently stated in a report that they expect console shortages to last for another 6 months. We're betting that the retailer's forecast is fairly conservative, as it's easy to imagine another 6 months of early mornings trying to hunt one down. The console has been hard to find since its launch, so another 6 months doesn't seem like much of a stretch to us, at all.
This is just the expectations of Gamestop, though, so should Nintendo emerge from the dark mist like some knight in shining armor, we would most definitely take our own foot and place it within our own mouth. But seeing as how Nintendo hasn't figured out how to satisfy demand issues yet, we're going to have to assume it'll take a while to get healthy Wii stock on shelves.