In a post titled "Customer Affinity", Martin takes on the dev / business relationship. Some nuggets:
It's important that a team has the (technology) working and under control, but I believe that the more energy goes into the business problem, the more effective at providing value a team will be.
The real intellectual challenge of business software is figuring out what the real contribution of software can be to a business. You need both good technical and business knowledge to find that.