Helping student to become engaged in the subject matter is important, bringing in guest speaker to talk about their expertise or field of student is very interesting to students and helps to motivate them.  Keeping abreast on new and exciting changes in their field of study helps to motivate the student and open new challenges that broadens the way they may approach or think about the career path they have choose.  This allows the student to explore areas of their field and maybe look in an area they have not thought of before.  This can help build self esteem for the student and create new information learned for the student.