My understanding of Odinism is that it is the explicit worship of Odin, without the other Æsir, Vanir, etc. Personally, I believe that the Norse faith was meant to include ALL deities, and the monotheistic worship of Odin is a bit too influenced by Abrahamic religions such as Christianity. Giving all power to Odin weakens the balance of power, and with no alternative deity, you enforce a single way of thinking.