The Patient of the Week - a porn star that turned out to be sick because his family sheltered him too much growing up - served the purpose of putting a mirror up against Chase and Cameron's problems this week.
There was a lot of discussion about morality and whether or not one can create one own ethical code, which is essentially what Chase did when he killed Dibala.
While Cameron started the episode by forgiving her husband, she also said the pair had to get away from Princeton Plainsboro. House surmised this was because Cameron blamed him for Chase's actions. While the marital strife played out, House tried to recruit Taub and Thirteen for his team again.
They initially resisted (a lot), but House appealed to their need for competition and mystery. As he faxed them the differentials for the patient, Chase made it clear to Cameron: he killed Dibala. Not House. He also told her that he wanted to stay on House's team and not run away from his problems.
Once House revealed that he actually knew what was wrong with the patient all along - but was waiting for Taub and Thirteen to call in with the results and come back to the team - Cameron knew what she had to do: she gave a great spech to House in which she did blame him for turning Chase into the man he's become. She said she felt bad for both of them because they'd lost their humanity and didn't actually care about the patients.
And, with that, Cameron left the hospital and her marriage.