The DR-DOS/OpenDOS Enhancement Project

Well, that is the same argument as for NTFS - I don't think DOS
needs either of them.

If Microsoft drops support for FATxx, they will create their own
interoperability nightmare. Not that it matters IMO - Microsoft has
not shown any interest in the PC market for the last ten years, and
they are not likely to change this in the coming decade, either.

I don't think that exFAT is meant to replace FAT32, anyway. With the
increase in cluster size, exFAT is clearly designed for huge static
data files only, unlike FAT32 which was designed to decrease cluster
size to save disk space for small files. Let's see how it fares when
FAT64 is released. ;-)