I kinda think Haruhi will not become a god but she still "wins" as if in matter - with whom Kyon will stay. Kyon doesn't dislike Sasaki but it's not good enough for him to break his relationship with Haruhi. He might admit that she is unfit to be the one with such power but he won't abandon her if she will become just a girl..
..or maybe that's the point, from all people around Haruhi, Kyon is the only one who still thinks of Haruhi as Haruhi and not some unexplained paranormal phenomen. Koizumi and Nagato shows a lot of times in novel that if it wasn't for her power, they wouldn't really side with Haruhi at all. Mikuru is completely different story but she also is there with Haruhi because of her oddity. Now they will surely side with her because they don't want to lose to their rivals but if she was to lose her power - for Haruhi only Kyon remains.
Some fans of this obvious pairing would say "Great, finally those two alone together", but I guess Haruhi wouldn't just stand for that.
..but if there was a battle in which Haruhi and Sasaki were to fight with each other with arguments, Haruhi wouldn't win. Funny thing is, Sasaki wouldn't win either, but she wouldn't lose too - she is a person who could accept the responsibility and then completely forget about it. Haruhi is already on losing position because Sasaki has really nothing to lose and - all is fun and stuff - Haruhi is really worse "god" than Sasaki.