I for one would like to see there be permission to celebrate the Extraordinary Form of the Roman Rite (the “Tridentine Mass”) in the Vernacular, which for me is English. The whole thing in English - but people could still use Latin for parts or all of it if they want to. I know there is not much demand for this and the type of people who like the Extraordinary Form tend to be those most opposed to changing it in any way, but I can always hope.
I also would like the Ordinary Form to be made more like the Extraordinary Form while keeping the reforms that have been good. The good reforms, in my mind, include having the priest say many things like the Eucharistic Prayer in an audible voice, adding an extra reading that is usually from the Old Testament, allowing laypeople to read the first and second readings, adding/“restoring” the prayers of the faithful, and making the dialogue Mass (with the people saying the parts normally said by the minister or the choir in a Low Tridentine Mass) the norm. There are many other reforms that were good.
What I would like to see be at least possible, though, is allowing the full prayers at the foot of the altar (with the old form of the “I confess to almighty God” said in turn by both the priest and the congregation (since we are keeping the dialogue Mass)), the three-fold Kyie Eleison, the full Tridentine offertory prayers, said at least mostly aloud, and the Last Gospel (although with the dismissal moved to after the Last Gospel) - I would like to see all of these be allowed in the Ordinary Form of the Mass.