In New Moon, after watching it for the fifth time, I was thinking about the end of the movie. I couldn't see how Jacob was going to have to be around Bella when she was a vampire. Then thinking about the 4th movie, I remembered that he was around ALL the time because of Nessie. Why? Because of imprinting. Then it dawned upon me- Jacob didn't mention imprinting ONE TIME in the movie. In the book, he goes into full detail about what it is and how it works. He talks about Sam and Emily, and him and Leah. This is a key factor to know about the next 2 books and why Jacob has to be around all the Cullens in the 4th book. Without explaining it in New Moon, they'll have to bring it up in either the 3rd or 4th book, neither making sense because that's when some people start to imprint, making it very important to be mentioned in New Moon.
Just go and check the books again,its actually in Eclipse where Jacobs explains about imprinting,and where the other wolf-boys start to imprint!! So dont worry about it,Im sure they will put it in Eclipse!!