We salute you, unnamed Target employee who leaks internal documents and places his own livelihood at risk in the process. Courtesy said nameless hero, the specific number of Wii units headed to each outlet has been (supposedly) revealed.
Instructions: head to this forum page and find your local store. Note its specific store number, then head to the previous page and cross-check your store number in the list. The second-to-last number in the line will be the number of units received by that store. The internet loves you, you know. In lieu of searching confusing forum page posts, just head here, type in your area code, and view the convenient results that spew forth from yon servers. It'll return several stores in the area, weighted by both proximity and number of Wii units available.
Some math reveals that the average number of Wii units per store is close to 46, a decent stock indeed. We know it'll be difficult come launch day, but with perseverance and and the ability to resist biting cold, you'll get your console yet.
[Thanks, Antibot and Elliott!]
[Update 1: Added better "Wii Finder" app]