According to an email sent from SimplyGames, "Thanks for bearing with us with whilst we finalised stock configurations with Sony." Apparently, customers MUST update their preorder and MUST choose one of the bundles, the lowest priced at £414.99, the others at £469.99.
Sony isn't pleased, despite SimplyGames' claim. "Sony is not and would not force anyone to buy something they don't want," Sony UK PR chief David Wilson wrote in a statement, "We value our consumers and offered the bundles precisely to give them choice and value. And the key word there is choice. We continue to work closely with our retail partners to ensure we offer this choice against the challenges of managing demand and inventory in the climate of amazing excitement and unprecedented demand for PlayStation 4."
The legality of this action by SimplyGames is suspect as well. The words that come to mind are "Bait and Switch", and Eurogamer's tipster stated that Trading Standards has been contacted. Stay tuned.
[UPDATE: Two £400 bundles with a game has been added to the retailers list of bundles, one with Killzone: Shadow Fall, the other with Watch Dogs.]