They should be in the shops from next week as they were being sent out yesterday and Monday. A batch was taken to Ally Pally for the retailers there. In case it's of interest to you, Hatton's are putting their pre-order price up from £22 to £24 on Monday.
At Ally Pally today they were on sale for £23.75 (The Signalbox), £27.95 (Hereford Models) and £30 (can't remember).