I do work there. I do have a company wide allotment report.
People forget that this is a very small section of the general population. Most people do not run to the store the minute they hear of the next Wii to pre-order. This is not an Iphone or hot cool gadget. It's a gaming console. Nerds, and people who choose this as a hobby know because they choose to.
Nintendo is in business to make money, and they have quite a few partners in retail (Walmart, ToysRus, Target, Bestbuy, etc.). Or did people think that ToysRus was really only going to get half a dozen consoles per store? Less than intelligent folks get on a Gamestop pre-order with no backup plan. ToysRus will have extra, and so will Target, and BestBuy.
Will you beat the resellers who are there at opening? Who knows, but as Prim says, stop assuming stores are getting a few units on launch day.