I’ve always held that quality interface design is by its very nature a cross-disciplinary exercise. Psychology, Aesthetics, Human Factors, Computer Science, Anthropology, Library Sciences, and more are all part of the equation. However, it seems that more practitioners and companies are finding success with increased specializations like Interaction Design, Information Architecture, Visual Design, etc.
Peter Merholtz recently touched on this issue:
“User experience feels like a term, and concept, whose meaningful time is over. The energy seems to be behind the terms and concepts of "information architecture," "interaction design," and "usability engineering." Maybe we should take that as a sign.”
User experience is, of course, a more cross-disciplinary or generalist approach to interface design and information architecture or usability engineering are increasingly specialist roles. There’s no denying that times do look good for fields like Information Architecture. But are deemphasizing the role of generalists that can bridge the gaps between these specialties? As Jim Leftwich put it:
“I have always believed in the speed, breadth of integrative power, and just sheer purity that a single strong design lead can bring to a problem. What separates truly extraordinary and transcendent products or systems from the merely adequate (I won't even talk about poor efforts) is vision. Until such time that the communication and coordination between *separate minds* can reach the speed and integration of neurons within a single mind with vision and experience, the latter will always be capable of creating and *inspired* solution.”
Tom Smith illustrated it well with his User Experience Curriculum: there are lots of points of understanding that inform the design process. Generalist thinking helps interface designers tie them together into an effective product solve.