This is a bit of a misconception. Nobody seems to remember the Wii launch very well.
The system's launch was not a big deal. I waited at Best Buy and bought one on launch, they didn't even sell out, and then I went across the street to Target and bought another. The Wii didn't become the big thing until about a week or two after launch. Resale prices on Ebay didn't get above $350 until a few weeks after and then the thing became impossible to find for months. The launch was very meh and it immediately seemed like the system would flop, the success only came after the system was out in the wild and word of mouth started to spread.
Maybe the Wii U can do the same.
Yeah I got a Wii off eBay a few days after launch for about $30 over retail. It was hard to find but the demand wasnt really there yet.
Seems the demand for Wii U is even less though and I dont know if word of mouth will help this time.