The factory sale has usually been held around the same time.
2010 it was Sat Nov 20th,
2009 Sat Nov 21st,
2008 Sat Nov 22nd,
2007 was the farthest date I could find but it was Dec 8th.
Excluding data prior to 2008, the pattern is pretty clear. Unless they radically change the venue of this years sale, I predict the 2011 Factory Sale will be held on Saturday, November 19th.
(26th is also a possibility.)