Edited to say:
Here's the theatrical summary, Maej26:
Here the therapist tells Evan (after he ends up in the mental institution) that there are no journals. He gets hold (from his mom) of his home videos, and goes back in time to when he first meets Kaliegh. He tells her he hates her and to never come near him again. Evan returns to the future, to a room he shares, I believe, with Lennie. He flashbacks how Kaleigh moved to her mom's house, her brother graduated from high school, Evan and his mom happy. Then the film cuts to 8 years later, Evan walking down a busy NY street, speaking on his cellphone. As he walks he passes a familiar person - Kaleigh, and for a moment each turns around and looks at the other person (but neither sees the other person do this). Evan, with what looks like great hesitation and emotion, continues on walking.
Without seeing the director's cut I think I prefer this ending where Evan has to live with the consequences of his actions. I haven't seen many films where a character gets the opportunity to change the past and at the end of the movie still remembers everything that happened, or that in the end of the film things don't go back to how they were before the character started making changes. Choosing to allow Evan to deal with the results of his actions while continuing to live is, in my opinion, a courageous and risky choice and makes a more interesting finale. Although friends of mine have argued whether Evan indeed remembers, 8 years later, everything that happened and that he hasn't forgotten since he destroyed all his journals. I think he remembered.