According to Best Buy's Retail Stock System (RSS), the number of available Wii systems per store is already established. The RSS states that there will be as few as 24 Wiis for the stores sitting out in the country, and as many as 120 for the more popular Best Buys situated in highly populated areas.
Also tied to this report is the status of Wii software availability. Each Best Buy may stock around 60 copies of Red Steel and 30 of Trauma Center: Second Opinion, although there was no word if the number of copies would increase with the number of available systems. However, it would make sense that the stores that received over 100 Wiis would receive more software copies.
Lastly, there is the possibility that some Best Buys have already received their first Wii shipments as the rumor listed "10/28 or 10/29" as the first time the store would get Nintendo's new system. Of course, the street date of November 19 remains the same, but it's an interesting tidbit nonetheless.
Nintendo was unable to be reached for confirmation, however several Best Buy employees were able to verify the projected numbers.