
a graph of all the #1 singles from 2005 to now
you'll notice very few are released in november or december. In fact, since 2007 no #1 singles have been released in nov or dec. The most recent is Irreplaceable by Beyonce - released in dec 2006.
So here's what i think. Single in october if the album is going to be released in early 2011. Single in jan/feb if it's going to be released after the 3rd leg of the monster ball.
If we don't have a single by the end of October there's basically no chance of seeing the album in jan/feb.