Some say there is a turf battle coming, I think it's a lack of understanding, and I think it's already here.
The battle we (they and I) speak of is the vision and strategy for digital products. We have these roles like Information Architecture, Interaction Design, and Visual Design... not to mention prototyping and writing code... then we also have these partners in the shape of Product Managers.
It's the difference between the 'product' and the 'experience' that's important to understand. There are process problems that the software can not solve elegantly... but with vision, and potentially through the interface, we can. There lies, just outside of your app, your site, or your software logistical problems... problems in space and time... problems that surface only through field work to understand the context of need and use. Being there, watching, listening, asking questions, and then putting the prototype in their hands (you know who) is the best way to try, fail, learn, try again, and ultimately... provide the solution.
The user's experience... it's much bigger than the product.