Another rather obvious trait for a good teacher is knowledge.  Teachers need to have a thorough knowledge of the subject they are teaching.  That is not to say that they must be experts in the field but rather that their knowledge of the material is extensive enough to approach to topic from a variety of angles in order to pass that information on effectively.  

But more than just mere knowledge, a teacher needs know-how.  He or she must be able, not just to talk about the material but, to put it into practice.  In other words, teachers must be able to use what they know.  Philosophical discussions are great but if you are supposed to be teaching then your students must be able to do more than just theorize about the topic.

Teachers that lack these two traits also lack something else, students who are engaged.  As soon as the first kids asks a question that the teacher can't answer, the group is lost.  Teachers must know their material, and know it well.