Using a non-relational store with Mezzanine would be an ambitious task, as Mezzanine makes heavy use of Django's ORM in a relational way.
However I was recently contacted by someone from the App Engine team offering to help ensure Mezzanine deployed smoothly onto it. I mentioned the above and was told that Django is now a first class citizen on App Engine, with relational data supported via "Google Cloud SQL" which is their MySQL offering: https://developers.google.com/cloud-sql/docs/django
I haven't gotten around to making sure everything works smoothly, but it's toward the top of my todo list, so if it doesn't deploy cleanly at the moment, it will soon.
Using a non-relational store with Mezzanine would be an ambitious task, as Mezzanine makes heavy use of Django's ORM in a relational way.
However I was recently contacted by someone from the App Engine team offering to help ensure Mezzanine deployed smoothly onto it. I mentioned the above and was told that Django is now a first class citizen on App Engine, with relational data supported via "Google Cloud SQL" which is their MySQL offering: https://developers.google.com/cloud-sql/docs/django
I haven't gotten around to making sure everything works smoothly, but it's toward the top of my todo list, so if it doesn't deploy cleanly at the moment, it will soon.