The game of AI, or cognitive computing, is definitely afoot and IBM's Watson looks exactly like the sort of hero we want today. From a brand positioning perspective, what impresses me the most is the language, especially the visual language. The content strikes a great balance between text, images and video, with case studies and explainers doing the heavy lifting when it comes to persuasion. All very clean, but warm and with a very human scale to it. In this context claiming the word 'cognitive' seems quite reasonable and not as pretentious as it might be in a more techy environment.
A great example is the music collaboration project with Axel Da Kid. Another, for an Australian example, is the collaboration with fashion designer Jason Grech as part of Melbourne Fashion Week.
What I deduce from my brief observation is that Watson's positioning works so well because it follows the maxim of keeping it short, simple and human. Or in this case, elementary.