Google Classroom opens its doors to all teachers today.
/As of now Google Classroom is available to all Google Apps for Education (GAFE) users.
Classroom is a tool within the GAFE that allows teachers to set up different classes, set projects, assign homework to groups and grade them all within a single space. Classroom also records student grades and progress. It should be a worthwhile assessment tool once you have begun using it with your students for a couple of months.
Remember, what you are using at the moment is essentially Classroom 1.0 and as such it is quite limited in it's functionality and flexibility, but so was everything in Google Apps when it was first released and Google have certainly demonstrated a commitment to upgrade and enhance their products continually.
It will take you all of about 2 minutes to set up your class and get cooking so all I can suggest is give it a shot and see where it takes you. You certainly won't be wasting your time fro my brief encounter with it so far.
Here are a couple of resources and links to get you started and I'd love to hear about your experiences thus far.