Professional or Hobbyist?

I've been doing a lot of menial tasks in the last few weeks and I cannot stop thinking about ways to improve the American Educational system.  I've mulled over a lot of different scenarios, but the one that keeps reoccurring in my thought process is heavily centered on teacher education.  In America we expect high school teachers to have a degree in the discipline that they will be teaching and we also expect them to have some background in educational instruction.  We expect teachers to learn everything they're going to teach and more plus educational methods all in a four year undergraduate course.  I can't help thinking that educators, secondary educators in particular, would benefit from a full bachelors degree, four years in their specific discipline, plus a separate certification in teaching.  I think we put too much emphasis on time spent in a classroom learning how to teach during undergraduate education.  I think all teachers should be required to have a "masters" or separate certification in education before they set foot in a classroom.  Education specific graduate degrees would limit the number of people qualified to teach and hopefully this limitation would allow only the best of the best into our nations classrooms.