The kyuubi's not stupid. He's going to help Naruto against Madara. I don't see him being buddy buddy with Naruto. I also agree with Jaggid in that the kyuubi will always try and betray Naruto to get free.
I really enjoyed his chapter. Madara and Kabuto set up a few new questions in 2 pages
I see the kyuubi and Naruto in a different dimension altogether. It's not like Naruto is always there but the kyuubi is. I do think it was poor choice on the author's part to put Naruto in there because it raises questions of how they can see what was going on in the battle through a clone