Comment 11 for bug 391044

I only know of one incompatible change that is planned but not yet commited. About the BSD partition numbering. Chainging the letters to numbers like for real partitions already done.
I don't think Robert likes the idea to maintain some ABI/API number and asking for grub-install run only if that is different then the one in /boot/grub, but maybe you could just file a wishlist report at this.