Not defending 4WP, but sometimes the manufacturers "release" products before they've made them. I've had this happen a few times, the product is launched via media releases, etc, and becomes "available" for ordering, sometimes with a ship date. Sometimes it is just pure optimism from the manufacturer, they just get way behind for whatever reason, and only after chasing them up forever do they actually say that the product won't be available.
I've had one particular product on order since December and must have had half a dozen ship dates from the manufacturer, and they've never met any of them.
Of course this makes no difference when you are waiting for the product. I'm a customer too, and get impatient as the next person, especially when promised a delivery date that goes and comes.