|Thank you for giving me the excuse to post this XD|
This rumor has been making quite the rounds on fansites and deviantart, it originated on a miniconference in ExpoAnimeUSA held in 2009, when the author gave an interview, and is now circulating again given that the manga is nearing an end in maybe a year or so.
The author allegedly indicated his love of Shounen-ai and that NaruSasu was his favorite pairing. He even collects doujinshi and fanfics.
According to this source, who republished a deleted DA journal,
"Kishimoto revealed that Sasuke was based on his best friend from High School, whom he admired and loved very much, and that Naruto was a reflection of himself and the adventures he would have liked to experience when he was young. He also emphasized that in the series there is not a love triangle, but rather a circle, like a fish biting its own tail. Naruto likes Sakura, Sakura loves Sasuke and Sasuke has special feelings for Naruto.However, he ended the note saying that Shippuden was going to be mainly about the fights and character development."
I don't know about that, but the issue at hand is that Naruto runs in Shonen Jump magazine, and it would be a tremendous editorial move to give the manga a shounen-ai ending. I'm not going to say it is completely unlikely, unless all of this has been exaggerated and maybe he was referring that the manga finale will have that subtext.
Other concern is the NaruHina, which has had very little development, with Hinata pining all these years for Naruto and him being ambiguous about it.