Hmmm I don't see why they don't keep it as just one film... Surely it's meant to appeal to Harry potter fans, and Harry Potter fans would sit through it. I mean, lotr3 was 3 hours 15 minutes and people sat through that. They just need to be bold about it and keep in mind that they have a very difficult audience in the HP fans to please, so they need to make the decision that's best for the film