After reading the recent talks I decided to leave here my 5 cents on the matter.
First of all, as one of the open-plots left from the original series, Rito confessing to Haruna is something that is bound to happen. This is not a bad end flag at all! Rather, it is an essential event necessary for Lala's, Haruna's and - most importantly - Rito's character development. If he is EVER going to have a positive, proactive stance towards the notion of a harem, that will only happen AFTER he had fully came to terms with his feelings for both girls, which in turns requires that he confesses to Haruna in the same way he did to Lala in the end of the original series.
I will say it again, Rito confessing to Haruna is an unavoidable turning point for this story. Still, I don't see it happening anytime soon. Because, when it does, the whole focus of the series will likely change. At the very least, we will have to wait until the Mea/Nemesis plot is solved first.
Regarding Momo, you guys are have a really shallow view of her. She is not scared of Rito. She simply has not realized her own feelings.
Remember that when she first stated her interest in Rito, she said she didn't mind if her position turned out to be that of a lover. At that point, her feelings for him could be easily described as raw erotic interest combined with a mild, innocent admiration. True love wasn't really there at that point. The whole Harem Plan was founded on those simple - and somewhat childish - views that she had back then (
when you think about it, the standpoint that those three sisters have on romance is really way out there... Then again, it is not really much of a surprise considering what kind of father they have). Those are also the basis behind her actions up until now.
The thing is, somewhere along the way she ended up falling for Rito for real. Yet, she has not realized the change in her heart. What happened in the shed was not that she became scared of being intimate with Rito, but rather she was surprised at her own reaction to his touch. If she was the same person she was in the beginning, she would probably just have reveled in the fulfillment of her fantasies. But things are never so simple when a maiden is in love.
Just like how Rito has to solve his standing issues with Haruna and Lala, Momo needs to mature a bit and acknowledge her true feelings.
Finally, I think that the idea of Mikado becoming part of the harem is unlikely at best. Just think how she was portrayed in this series up until now. She is the "reliable (
) adult" that the other characters can run to in times of need. A teacher. Maybe even a parent-like figure. Most definitely not a love-interest. I believe Saki has more chances of joining the harem than Mikado does (and we all know what Yabuki said about Saki...).
On another hand, I can see Tearju falling for Rito somewhere in the future. Hell, I wouldn't be surprised if it turned out that she was introduced in the story just so that there was a MILF among the harem members!
