A return to the status quo? Perhaps, but it was nice to see how much has changed since the first episode. Kyousuke, who was drifting through life with Manami now feels compelled to chase the sister he used to hate to America. After discovering her secret and choosing/being forced to involve himself in her affairs his life wasn't so ordinary anymore. He made friends with Kuroneko and Saori and began his gradual conversion to otakudom.
Then she decides to go, and he is left to live without her. Though she is no longer his connection to his new friends she has still managed to grab a place in his heart, maybe it was always there. Kyousuke copes and has a genuinely good time without her, but he still cant shake the feeling that something is missing. The message from Kirino forces him to acknowledge this and Kuroneko gives him the push to do something about it.
He finds her in a sad state and she confesses why she hasn't been communicating. Kyousuke decides to get her to come home not for her sake but for his. His proclamation that he might die seems to show his pent up frustration. It may be due to the as of yet unanimated scene showing the breakdown of their relationship, as the pictures in the OP and the short story in the dvd box shows she and him had a good relationship.
Also
she's back!