I'll speak to generalities, but if he were pursuing an orchestral or band instrument and had a strong interest in teaching, I'd say you might want to begin to look at music ed (available as a BM, BA, and occaisionally a BS depending on the institution). Piano (and harp) tend not to be instruments offered instructionally within most (if any) public music school programs, so unless he has an interest in teaching general music at the elementary level, the music ed degree may not be the way to go.
Within piano study at the college level, you will find many programs with a performance/pedagogy emphasis, which is geared more to individual/studio instruction than classroom instruction.
There's a piano teacher or two on the board, as well as a few current college level students who can provide much more instrument specific advice.
Regarding if your current teacher is right for your s, there are no automatics in determining if the holder of a BA, BM, MM, GPD, AD or DMus is the right choice. Many master performers are terrible teachers.
Personality and interaction between teacher and student must be compatible. The teacher should be able to assess and develop a student's talent without riduclous demands, building and stretching skills as opposed to demanding perfection; the student should look foward to the lessons and practices. A good teacher will communicate openly, and advise if they feel they are "not right" for a student or if a new teacher is needed to bring him to the next level. You should take a trial lesson with teachers if you do intend to change, as it's a means of determining teaching styles, teacher/student interaction.
A few teacher advice threads are here:
Importance of Master Teacher? Does a phenomenal applied teacher really trump everything? What if your child's HS music teacher stinks? New Teacher-advice
Also, BassDad's great post
So You Want To Be Music Major - One Family's Experience is a must read for both general and specific advice.