From Eurogamer, changes to dun, dun, dun! The Steam Sale!
According to an e-mail sent to developers, the T-Day Steam sale (Nov 25- Dec 1) and sales beyond that will no longer have, say, GTA V on sale for a few hours at a big discounts and then pop up to a more modest discount. Rather, the sale price will be constant through the entire sale and the items on sale will just cycle through the front page. (And the end of the year sale is Dec 22- Jan 4.) It's suspected that this might be a change to accommodate Steam's refund policy to keep people from buying stuff and then returning it if it goes on sale further.
So, to sum up- no more daily sales, just a week long sale of stuff.