Allegedly Sony are giving us a 10% discount code for the down time over Xmas. Obviously they aren't wanting to let us use it while the January sale is on but you can if you're a bit sly.
Just put the sale item in your basket and keep it there. When the sale ends the items in your basket will still be at the sale price, ready for you to apply the discount code when you check out and buy them. Don't forget the discount apply to all items in your basket, so hang onto it all long as possible if there's something coming soon you're going to buy.