We all know by now that the seventh Harry Potter movie is actually the seventh and eighth Harry Potter, as its producers decided to release it in two parts, of course, for the viewers’ sake, so as to incorporate every element of the book into the film.

But there is another side to it, that’s for sure, as Harry Potter is not just a movie inspired by the books of J.K. Rowling, but it is also a mega-hit in terms of box-office, which means the “one book – two movies” strategy is actually a pretty good investment for Warner Bros Pictures.

‘Harry Potter and the Deathly Hallows’ is expected to appear onscreen in 2010, followed by the second part just months later. “We feel that the best way to do the book, and its many fans, justice is to expand the screen adaptation of ‘Harry Potter and the Deathly Hallows’ and release the film in two parts,” said Jeff Robinov, president of Warner Brothers Pictures Group on Thursday.

So far, Warner Bros. made an estimated $4.5 billion with the first five movies of the series, and is expected to add some more to that after the release of the sixth movie, ‘Harry Potter and the Half-Blood Prince’ in November this year.

As J.K. Rowling didn’t make any announcements on an eighth book coming anytime soon or anytime in the future even, it’s no wonder the producers want to hold on to the story as much as possible, and seize every opportunity their get with the Harry Potter franchise.

Huge opportunity for the giant studios, one more reason for the Harry Potter fans to break into endless discussions on how the producers are planning on splitting the two parts of the movie, and just another reason for analysts to calculate just how lucrative this deal actually is for Warner Bros.