Doesn't matter, you still die.
According to Warner Bros, the book had too many details with significance that it would end up misleading and incomplete if any of it was cut out. C'mon you know it's true. There are some of the movies where you feel unsatisfied coz it didn't play out exactly like it did in the book. So, I guess Warner Bros just wanna give Harry the proper goodbye. The first part is due to premiere in November 2010 and the second in May 2011.