Interesting discussion. I recently saw "a serious man" by the Coen Brothers, and the movie starts with about 15 minutes of Yiddish and I too was amazed by its similarities with Swiss German (at least on the matter of prononciation). Speaking of which, as a native Dutch speaker I can confirm that Swiss German has a lot of the same sounds as we use in Dutch. Even the speech rythm is so alike that I sometimes think I hear people speak Dutch when in the end it's just plain Swiss German.