Appears a number of pre-release titles have dropped price at Amazon to £39 which is the cheapest I can find which include:
Batman Arkham Knight
Tom Clancy The Division
Also Assassins Creed Unity is at this price
Shame Uncharted 4 isn't. Appears its dropped to £45 from £49.99. I had these on my preorder list and noticed the drop today. Worth cancelling and preordering at new price.
Hope it helps someone.