so he may understand the behaviour and patterns and be able to evaluate forms, interactions and user flows. User experience designer must be a good visual designer, so may build an appealing information architecture which is useful, useable and pleasant. UX designer needs to have a good grip over problem solving activities, the one who is able to segment a problem into sections and solve them effectively.. then bring those segments back to give a holistic and smooth experience for the user. UX designer also needs to be technology and development savvy so the solutions he may design are practical, economical and implementable. He needs to be a good data collector, a researcher and analysers.. so he may identify problems and provide effective solution using successful strategies working out there for others. He must be able to familiar with the global fights between products and platforms, so the solutions he may design would be flexible, adoptable and liveable until next round of improvement. 

But apart from this spectrum of skills, role of UX designer would evolve and absorb more elements of behavioural sentences than the other.  Few years down the road, User Experience Designer would be expected to be an influencer keeping an ability to induce users to perform something... Just like a psychic conductor and a persuasive architect playing orchestra of human experience using instruments of visual and emotional psychology, using tools of neurolinguistic sciences, suggestive influences. Such Persuasive Architect will use “next-gen” elements of emotional experience which won't be palpable by the user. It wouldn't use "buy-me", "sex" and 1% opaque images but a rhythm of ordinary controls, form elements, images and text labels to get the job done. The qualification criteria for such experience designer would be his ability to seduces, induces and incites users to lead users to their goals as well as organizational tools and give users and memorable and lasting sense of completion, achievement and satisfaction.  It is still few years ahead down the road but it is something which User Experience Designers would need to be, so they better get ready.