I noticed that a number of the professionals that have been interviewed how important it is to be well read (some even mentioned being well read outside of your discipline). They seemed to have a passion for learning and that was one of the things that they enjoyed most about their work--the opportunity to continue learning even after their formal education had ended.
Many of the professionals interviewed also talked about the importance of managing relationships, working with stakeholders, soliciting feedback, etc. It seems like a certain amount of humility is necessary in all of this because designers are constantly being asked to incorporate the ideas of others into their designs. An attitude of "I have all of the good ideas" or "No one does it better than I do" could be dangerous in doing this kind of work.
All of this reminded me of a book that I read over the summer called Learning in the Light of Faith. It is a collection of essays that were adapted from a lecture series that was offered at BYU back in 1995 and features essays by Pres. Eyring, Pres. Samuelson (before he was affiliated with BYU), Elder Maxwell, and Elder Oaks among others. The theme of the essays is "disciple-scholarship" and I noticed that every author mentioned humility, meekness, or a related concept as being key in learning. In another talk by Pres. Eyring (A Child of God, a 1997 Devotional Address) he discusses the attributes of great learners and mentions a willingness to "seek correction" as one of these attributes.
It has just been interesting to see all of these things coming together and to realize how important this humility and passion for learning is in our field.