Full disclosure #1: Things with tag lines like "It's free. Completely free." generally make me nervous. Google's "Apps for Education" is a big exception. The core offering of Web-based email, calendar & documents for collaborative study is cool but not particularly novel. Partnerships with disruptive carriers like YTL that hack around infrastructure limitations and get schools in developing nations online with 4G high speed wireless via Chromebooks, on the other hand, certainly are.
Full disclosure #2: Yes, I work at Google. No, I had nothing to do with creating Apps for Education (sadly!) and have not vested interest in promoting it.