If last year is any indication, expect consumer searches on "free shipping" to nearly double in the next two weeks.
Looking at Google's trend data, you can see the clear spikes in consumers searches for free shipping every holiday.
If you overlay the data to compare year-over-year, you can see that this year is on track to beat last year's trends.
Last year the top five weeks for the year were
Nov 18 2007 2.38
Nov 25 2007 2.68
Dec 2 2007 2.68
Dec 9 2007 2.60
Dec 16 2007 2.04
These numbers were up 70% over the early November numbers.
Don't wait for the media to report on it though. If you look at last year, the news reference volume clearly lagged the consumer searches.