In the commentary track on the tenth episode of the first season of HBO’s Game of Thrones DVD, David Benioff, co-creator of the show reveals an amusing secret about one of the severed heads seen on spikes: “The last head on the left is George Bush” and then his partner chimes in “George Bush’s head appears in a couple beheading scenes.”
“It’s not a choice, it’s not a political statement,” explained Benioff. “It’s just, we had to use what heads we had around.”
A likely story…
They’ve got the video at io9