In a recent press release Warner Bros. announced that they will push Harry Potter and the Half-Blood prince from a Thanksgiving weekend release over to July 17, 2009.
in their press release they wrote:
"Our reasons for shifting 'Half-Blood Prince' to summer are twofold: we know the summer season is an ideal window for a family tent pole release, as proven by the success of our last Harry Potter film, which is the second-highest grossing film in the franchise, behind only the first installment. Additionally, like every other studio, we are still feeling the repercussions of the writers' strike, which impacted the readiness of scripts for other films--changing the competitive landscape for 2009 and offering new windows of opportunity that we wanted to take advantage of. We agreed the best strategy was to move 'Half-Blood Prince' to July, where it perfectly fills the gap for a major tent pole release for mid-summer."consequently, Disney moved Bolt's release date up a week to November 21, 2008 in response to this announcement.