Now we have seen both of Bee's forms. The eight tails cloak and the merged form. As well we have seen Naruto's nine tails cloak, but the only time we have seen the merge form is when he is consumed by hate when fighting Pain.
From what I remember right there is a problem with Naruto taking on the merged form of Kyuubi. I am pretty sure it has something to do with the fact that the Kyuubi is full of hate. We also know the First Hokage could control the Kyuubi as well.
So I am not saying it will happen, but what I think and what I would LOVE to see is Naruto be able to tame the Kyuubi's hate and be able to summon him in a way to be his own form.
Meaning that instead of merging with the kyuubi, being able to let the chakra form outside of his body. So instead of Naruto merging he could let the Kyuubi at for a given amount of time to fight along side of Naruto.