Apparently, that is already the case for certain countries:
> Citizens of the following countries are required to have airport transit visa when they are passing through the international transit area of airports in Germany: Afghanistan, Bangladesh, Democratic Republic of the Congo, Eritrea, Ethiopia, Ghana, India, Iran, Iraq, Jordan*, Lebanon, Myanmar/Burma, Nigeria, Pakistan, Somalia, Sri Lanka, Sudan, Syria and Turkey.
> Citizens of the following countries are required to have airport transit visa when they are passing through the international transit area of airports in Germany: Afghanistan, Bangladesh, Democratic Republic of the Congo, Eritrea, Ethiopia, Ghana, India, Iran, Iraq, Jordan*, Lebanon, Myanmar/Burma, Nigeria, Pakistan, Somalia, Sri Lanka, Sudan, Syria and Turkey.
http://www.immihelp.com/visas/germanytransitvisa.html