People who need it now will buy now, price drops may come later with the AMD release but many people are willing to pay £50-100 extra now to get the enjoyment out of it for the next couple of months.
Remember as well your old card is going to depreciate more if the 480 is as cheap as claimed so the net cost of early adoption probably isn't that much in the grand scheme o things.
Remember as well your old card is going to depreciate more if the 480 is as cheap as claimed so the net cost of early adoption probably isn't that much in the grand scheme o things.