A discussion with the manager of a design group at a local company prompted me to think about the difference between designers and consultant/designers. The manager said that he had some talented graphic designers that he basically kept away from business areas that required design services. Others in the design group or on the projects they worked on acted as the interface to the business areas. There are good, defensible reasons for that. Business people can suck up a lot of time from creatives, asking for concepts, mockups, and ideas, and then rejecting anything that is presented with indefensible requests for changes (see previous blog post on this subject). This can work well if the manager understands the value of the designers' abilities and their time, knows how to manage clients, and isn't simply trying to take credit for the group's work.
On the other hand, being able to lead engagements and work with business areas and clients is a valuable, transferable skill. Leaving the consulting part of a project to someone else, especially someone who doesn't understand or can't sell the value of design, can result in some very good design work being underutilized or ignored. I've seen the same thing with usability analysts who worked only at the direction of a project leader. They couldn't assert themselves in project situations or consulting engagements, and as a result their test results and recommendations were largely ignored.
Personally, I'd like to see every designer and usability pro be able to lead engagements and consult effectively with clients.