I had three issues when doing an OpenSolaris liveupgrade from build51 to build57. Here are the solutions.

(1) grub menu entries were not updated correctly

# vi /boot/grub/menu.lst

title build57
root (hd0,0,a)
kernel$ /platform/i86pc/kernel/$ISADIR/unix
module$ /platform/i86pc/$ISADIR/boot_archive

title build57 failsafe
root (hd0,0,a)
kernel /boot/platform/i86pc/kernel/unix -s
module /boot/x86.miniroot-safe


(2) zfs did not mount because the mountpoints were created during liveupgrade

# zfs umount -a
# rmdir [zfs-pool-directory]/*
# rmdir [zfs-pool-directory]


(3) "The application gnome-volume-manager has crashed." when loading the desktop

# svcadm enable hal rmvolmgr
[via OpenSolaris Forum]