I guess.. Naruto's chakra natures will most likely be wind and/or fire and/or lightning. I don't really see him as a earth-type or water-type.. Fire is a huge chance with the kyuubi inside him and all and wind is just because it's rare and Naruto is kind of a rare wind-type anyway. Well.. His personality sure isn't like lightning, but because he
I don't really know if those were the exact words of the rap, but that's the only thing that makes me believe he'll be even close to lightning-type chakra nature. And also, the orange hokage thing makes me believe more and more about him being a fire-type...
mastered the kyuubi and the kyuubi's chakra, he will become more like his father. Like what Bee said "Quick steps and a big smash, but all I saw was a YELLOW FLASH"