"Michal" was one of the Biblical names embraced by Zionism, very rarely found in pre-Zionist communities. It is a very common female first name in contemporary Israel. Michal is not a form of Michael, but possibly means "brook," or "stream." - http://en.wikipedia.org/wiki/Michal
According to Louis Ginzberg (Talmudist and leading figure in the Conservative Movement of Judaism of the twentieth century), the Rabbinic tradition is that she (Michal) was of "entrancing beauty."