Usually, the more technical they are, the more they lack communication skills. I would dedicate people to work full time at understanding how to communicate and making sure that it actually happens throughout the project. Communicating up the ladder, to senior executives, is a little different. So there's a different aspect to the communication flow. They're much less interested in telling the higher-ups how the system is going to work and getting input on what the system will do than in making sure that the executives have enough information to lead effectively.
Every big project is about attaining some strategic business aim.
You may be implementing a sales automation support system, but if you forget that the goal is to double sales and expand into a new region, you'll get disconnected. You have business goals, then systems goals and project goals. The lower caste of goals must not be completed at the expense of the overarching aims. For example, a project team may have a goal of completing programming on a module by Aug. 1, and they make the deadline by cutting some corners that violate certain larger system requirements dictated by business goals. This is a real chance for miscommunication between the technical and business people.