For self-contained teachers this immediately solves issues with distributing and collecting Google Doc files. It's also a place for students to communicate questions with their classmates or you. While the interface is limited and the themes are pretty basic, I think the potential for this product is astounding.
From my new perspective of a push-in support teacher, I see this as a way to push out modified assignments to students. Part of our new reading curriculum involves discussion guides and we, as a special education team, are considering modifying them so they are Google Docs. This would give me a way to push out specific docs, to specific students easily. I also think giving students a place they can post questions might be useful, especially students who may not want to speak up in class. I can see it as a way for those students to contact me when we are not together in class.
I'm going to continue to give it a try, and see if there are other ways it can be utilized. I'd love to hear some of your thoughts on using Google Classroom. This week Google opened it all users with GAFE account, but there is one caveat. You and your students must be on the same domain. This is actually a problem in my district, my email ends in "d57.org" and our students are "students.d57.org" so I cannot create a Classroom unless I have a different login. This is frustrating, but Google is aware and hopefully they will fix it in the near future.