Windows 7 Upgrade Pro version spotted at Walmart tonight (OCT 18, 2009 @ 22:30).
However, it was not on the right shelve and had no price, but there was total of 3 retail boxes wrapped up in retail spider web. To see pictures see:

http://img21.imageshack.us/i/10182009175.jpg/
http://img11.imageshack.us/i/10182009176.jpg/
http://img21.image shack.us/i/10182009177.jpg/