The final three episodes of the not so subtly titled, "My Little Sister Can't Be This Cute", has come out; and after leaving the series on a flashback episode, they certainly put their foot on the gas in these last few episodes. And because there was this straight and narrow approach to finish up the plot, the overall finale felt rushed.
With that rapid dash to the end, anything and everything felt really easy for a relationship that was as taboo as incest. Everyone was very respectful and accepting of Kirino and Kyousuke's relationship with not much effort, and that felt really unrealistic to me. Honestly, the saving grace of this arc was Manami; she was the only one that stepped up to play the villain, and I loved her more for that.
Before Manami came in to regulate, I thought that she was going to get shafted, and not even be addressed with this sea of praise all from the people Kirino and Kyousuke usually spend time with. But me not being much of a fan of childhood friend characters, I didn't mind too much. So when Manami came into scene with Kirino around, I was excited for some conflict after the wincest fantasy. And did it feel good to see Kirino get hit by Manami, not that I'm for violent, but Kirino needed to be brought down a peg after pretty much walking over everyone -- because she never really suffered any consequences for forcing people to do it her way, throughout the series.
As for the relationship itself, I was pretty disappointed that Kyousuke picked Kirino; not because of incest, but simple because I didn't like Kirino's personality, and was hoping for the title to be an ironic thing, rather than foreshadowing. Not only that, with the limited amount of time and the anime desperately trying to establish this relationship, it didn't have or say much to convince me to be happy for them. In the end, it was a weak relationship that most people could see coming from planets away, and ended pretty abruptly.
The ending itself felt a bit strange that after Kyousuke sacrificed so much, and Kirino wait for so long, to end that love with a kiss and everything is back to normal. They might have made too much emphasise on a relationship for it to stop when they graduated, and just became regular sibling all over again.
To me, OreImo was a pretty entertaining piece of stereotypical romantic comedy, but I wouldn't say it offers too much on taboo relationships, like incest. This is probably one of the better, more thought out, no-so-serious romcoms about falling for your sister. However, if you want something that is far more mature and better put together anime about incest, I would recommend Koi Kaze.