Same question here. I used to be able to receive email notifications when my wife made changes to a shared reminder list.
Today I have set up a new shared reminder list (Christmas shopping!). When my wife makes changes to this list I am not notified of the changes she makes.
I have other shared lists (pre-iOS 6) where I am still receiving email notifications when she makes changes.
I have been looking everywhere for a new menu/options/settings, but can't find anything.
I concur exactly GeneralFranko. I still get emails from old reminder lists but none from any that I set up now. There use to be a box to check that states "email me when reminder updated" but that box is now gone. I have looked everywhere and cant find anything. This last update for Reminders was a huge step backwards!