Studio boss Alan Horn cited “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.� Apparently, the move was subordinate Jeff Robinov’s idea. But he�confirmed that the release date change does not alter the production schedule for�the two-part�Harry Potter and the Deathly Hallows.

This is surely a huge disappointment to millions of Potter fans. Hopefully the movie is really good to make up for the extreme delay!

Source: Deadline Hollywood Daily