Here's the changelog:
* Wed Apr 29 2009 Peter Jones pjones@redhat.com - 0.97-50
- Handle virtio_blk disks and their crazy new device name in grub-install
(rhbz#479760)

• Thu Apr 16 2009 Peter Jones pjones@redhat.com - 0.97-49
• Fix efi booting on machines with continguous memory regions across
  the 1G boundary.

These are both very low risk; the -49 build can only effect EFI users, which are few and far between, and the virtio change is an addition to a regexp:

• sed -e 's%([sh]d[a-z])[0-9]*$%\1%' \
• sed -e 's%([shv]d[a-z])[0-9]*$%\1%' \

which allows users to install onto virtio_blk disks.