I noticed something. If Sasuke knew that the sharingan's "true purpose" is to control the kyuubi, could that be the reason he was able to supress the kyuubi's chakra in Naruto when they meet at Orochimaru's lair.
Like Jiraiya said, someone must have summoned the kyuubi when it appeared at the village, and we can safely assume that that was Madara. My other thought is how vital was the kyuubi to the formation of the village, considering that both of the founders had some level of control over the kyuubi (like Naruto and Sasuke o_O).