I'm in the same boat and I havent tried this yet but was considering to do so: There is a new "remind me to grade by... date" in assignments. Setting this date will cause the items to grade to appear on the teacher dashboard. What I was going to attempt to try was setting the 'remind me to grade by date' to be the first day of class, hoping that all submitted assignments would then appear on my teacher dashboard throughout the year....
Again, haven't tried it yet but figured I'd share...