[Book Spoilers] Littlefinger's Role in Future Episodes?

[Tewks44]

A scene that really bothered me was when Tyrion was telling Little Finger about his next scheme. He said that he would like to see Jaime released, and Little Finger would profit because he would be able to see his beloved Caitlyn. From what I could gather Tyrion is going to send Little Finger to negotiate Jaime's release. Being somewhat of a purist this scene really bothers me. First of all, in the books Jaime's release wasn't made evident until the beginning of ASoS, so if it's in the 4th or 5th episode they have REALLY pushed it forward. Secondly, Caitlyn released Jaime on her own accord in the books, she didn't negotiate with Little Finger. Also, what does this mean for Little Finger? I can't remember what Little Finger's role was in ACoK to be honest, but will this significantly alter the role Little Finger will play in the story?