I just watched this film yesterday. Natalie's character, Alice (who was the nicest character in the movie... so innocent while the other characters were scheming), was ENFP also in my opinion. Anna was an IxTx. Dan, I thought, was an INFP "gone bad", but I could be totally wrong about that! He could be also ENFP or ESFP, as other people have suggested.
Larry, I think, was an ExTx.
I'm not sure, however, if the characters in this film had distinct personality types. As someone on IMDb wrote, the film is more about the connections between people than about the people themselves. Anyone who has cheated or been cheated on can relate to these characters in some way, whether they share personality traits with them or not.
It was intriguing how all the characters lied about something. Dan lied about his feelings, Anna lied about the sex-- Alice/Jane was sincere about her feelings and sexuality but she lied about her identity. And Larry-- did Larry lie about anything? Perhaps not. Perhaps he was the most honest of the characters (although he did plot against Dan at the end of the movie).